·LIST OF PLATES. PLATES. 11 PT PLATE 1 SCALES TO PACE PAGE 13 3 COXTENTIOXAL SIGgg ASD LETTERING USED IN FIELD SKETCELITO 17 3 CONTEXTIONAL SIGNS AND LITTFRING CHED ON ORDNANCE STRULY Mars 19 4. SLOPES 21 TIACACRIYO AND COXTOC R3 (! Os Mar) 4T ESD Or Doox 6 COLOTRLD SIAP JXDIAX JAP 19 11 1 . 1 » 1 $ 9 10 19 7 40 71 19 19 71 0 11 91 07 17 71 *1 40 9. 19 s 67 16 10 11 10 01 CAXADIAX Bar 10 GERMAN Mar 1). FRESCI BIAT 12 HAR OF SWEDEY ON THE LATYR SYSTEX 13 PETS ATIO COMPA: TO PACE PAGE 30 14. SERVICE PROTRACTOR 33 13. LINES OF EQUAL MAGNETIC SABIATION 16 PUAN TABLE 17. CONTENTIOYAL BIETHODS OP SHOWING OBJECTS IN NATURE • AT END OP BOOK 18 LANDSCAPE SKETCI Or For HILLS 13. PANORAMA FOR USE FBOX AX ARTILLERY TOSITION 194. RANGE-TAKERS' CARD 20. EXAMPLE OF A LANDSCAPE SKETCH (CHITRAL EXPEDITION) 21. EXAMPLE OP A LANDSCAPH SKETCH (BATTLE OF LIAO-TANG) 22 SPECIAL "BAP or ENGLAND FOR TRAINING PURPOSES 23 totoo OB " MAP OP N W. EUROPE 24. BELCIUM. Todo TACTICAL MAP 25. INDEX TO FRENCI ŠOU AND BELGIAX Toobas MAPS Nate.--Plates 5, 6, 7, 8, and 12 have not been incladed in this edition, but four Dow plates have been added. 1 90 70 11 11 * 11 D 1 . ... 19 19 140 M .. 11 11 CO JD

·MANUAL
OF
MAP READING
AND
FIELD SKETCHING.
PART I.
CHAPTER 1.
INTRODUCTIOX.
1. This manual iş intended for the use of candidates for com.
sketches for military purposes.
All regimental others must be so trained as to be proficient in the
following subjects
If
to an existing roap or
to an enlargement.
iv. A certain amount of sketching on blank paper.
Selected officers, who show special aptitude in is, should receive
further instruction in sketching on blank paper (see Part II).

·LIST OF PLATES. 49 7! N . n 41 w pe II 11 T+ 19 40 95 90 11 19 PLATE J. SCALES To Face PAGE 13 CONVENTIOX IL SIGNS AND LETTERING CSED IN FIELD SKETCHING. 13 3 CONTENTIOBAL SON AND LETTERIXC LXED ON OEDVANCE DRVET VAT 19 FLOTES 3 MACOCRINO AND CONTOCR3 (1 OS far) IT ExD or Doox G COLOCRED JI Ar 7 JADIAN Bar 8. 9 CAXADIAX Har 10 OCENAX Var 11 FAEXCA JAP 12 Mar op RWEDEY ON THE LATTS SYSTEX 13 PETSUATIC COMPAsg TO PACE TAGE 30 14. SERVICE TROTRACTOR 33 13 LIXES OF EQCAL MAGNETIC VARIATION 40 16 PLANE TABLE 67 17. CONFESTIOYAL METHODS OF SHOWING OBJECTS JX XATURE AT END OY BOOK 18 LANDSCAPE SKETCH OF Fox HILLS 19. PANORAMA FOR USE YON AY ARTILLERY TOSITION 194. Raxoz-TAKERS' CARD 20. EXANTLE OF A LANDSCAPE SKETCR (CHITRAL EXPEDITIOX) ... 21. ESANTLE OP 4 LANDSCAPH SKETCH (BATTLE OF LIAO-YAXC) 22. SPECIALI"_BIAP OP EXOLAND POR TRAINING CORPOSES 23. Taboo OB " BIAP OF N 14. EOROPE 21. DELODY. TOTO TACTICAL MAP 25 INDEX TO Frenci rodos AND BELGIAN Toost MAPS Nalates 5, 6, 7, 8, and 13 BATC not been included in thla edition, but Tour Dow plates have been added, 21 190 19 11 10 . N T! 1 11 11 11 30 av. N 1 n 10 1 9 1 17 DO + 11 7 . 01 09 1 15 . 11 ·7 2. A military map or field sketch slıould show all the features of, or in, a country, naturnl and artificial, which are of importance from a military point of view, ie, those which might affect tbo dispositions, movements, security, or supply of troops A military map is the work of a trained surreyor, using special instrumenta and elaborate methods, with unlimited time at his disposal, and aiming at minute accuracy. A field sketch is a sketch of ground made with such instruments and under such conditions regarding time, weather, etc, as generally exist in the field. 3. Military maps may be conveniently classified into strategical maps on very small scales, small scale maps, and large scale maps Strategical maps are used for conducting the operations of an army as a whole. Examples of this class are the moodogo (about 16 miles to 1 inch) and the 6 mile to 1 inchi map of Belgium and NE. France Small-scale maps, such as maps on the scale of 1 inch, 1 inch, or #inch to the mile (or similar scales) are required to assist troops to manæuvre and fight Of these, maps on the scale of 1 inch to the mile will usually only be available for the use of the higher commanders and their statis. Subordinate commanders and regimental officers will normally be supplied with maps on the scale of inch or 4 inch to the mile Large scale maps (2 inches to 1 mile and upwards) are not always available in war When available they would only be issued to certain units in small quantities. They are especially useful, when squared, to heavy artillery working in co-operation with aeroplanes. 4. Field skelches, which are usually made on a scale of from 1 to 4 inches to 1 mile, are of two kinds, They may be occasionally required to illustrate in detail the disposition of troops, to indicate lines of advance in attack, or to represent minor features of ground of tactical importance when maps are not yuld be as accurate as the minute accuracy duction of his map is These sketches are executed by officers who have received special instruction, and are usually carried out with special instruments, such as the plane table Rough field sketches are also required in the circumstances described in para 1 iv above Every regimental officer, and ·0 1. Alap nading An officer, or non-commissionel oficer, may be mid to le proficient in mp rating when on ciamunalinn a map contes to Pum a clear impression of tho ground features a, represented by contours or sailing, and of all the natural or artificial fetures Cilbited on the inip. Further, he slould lo able to identifs liis position on the ground quickly and to recognize all visible objects morher on the map This requires close study and constant practice, and is un important branch of nuhury education Wap enlarging This should Ixe crecuted by the methods described in Chapter VI, usually the scale of thic enlargement sill not cxceed 1 inches to 1 mile. all idiling lopographical information to a map. This comprises ope of the most prolzblo and most important duties in sketching that an officer mis be detailed to carry out in the field. Troops will rarely not bo operating in an entirely unmapped country, but the existing maps will often fail to give the military information which is essential to the conduct of operations. Oficers may thercfore be employed op service, on work of this nnture. iv. Sketching on blank paper. It will occur, though possibly rarely, that no map exists of a locality. It is therefore necessary that officers should be able to make a sketch. Such a sketch is not intended to be an accurate sur cy, but must include all information wluch is likely to affect the military object in view, It should also be remembered that a rough sketch to an approxi. mate scale is a valuable nddition to a written report on a locality, and should be executed whenever time permits, if it is not possible to enlarge an existing map and add such information as is necessay to the enlargement.

·7 2. A military map or field sketch should show all the features of, or in, a country, natural anel artificial, which are of importance from a military point of view, ie, those which might affect the dispositions, movements, security, or supply of troops. A military map is the work of a trained surreyor, using special instruments and elaborate methods, with unlimited time at his disposal, and aiming at minute accuracy. A field chetch is a sketch of ground made with such instruments and under such conditions regarding time, weather, etc, as generally exist in the field. 3. Military maps may be conveniently classified into strategical maps on very small scales, small scale inaps, and large scale maps. Strategical maps are used for conducting the operations of an arıny as a whole. Examples of this class are the foodoro (about 10 miles to 1 inch) and the 6 mile to 1 inch map of Belgium and N.E. France. Small-scale maps, such as maps on the scale of 1 inch, incb, or 4 inch to the mile (or similar scales) are required to assist troops to manoeuvre and fight Of these, inaps on the scale of 1 inch to the mile will usually only be available for tho uso of the higher to certain units in small quantities. They are especially useful, when squared, to heavy artillery working in co-operation with aeroplanes. 4. Field sketches, which are usually made on a scale of from 1 to 4 inches to 1 mile, are of two kinds. They may be occasionally required to illustrate in detail the disposition of troops, to indicate lines of advance in attack, or to represent minor features of ground of tactical importance when maps are not available for enlargement Such sketches should be as accurate as time and the means available will permit, but the minute accuracy which is required by the surveyor in the production of his map is not expected and should not be attempted. These sketches are executed by officers who have received special instruction, and are usually carried out with special instruments, such as the plane table. Rough field sketches are also required in the circumstances described in para. 1 iv above. Every regimental officer, and ·8 a proportion of non-commissioned officers, should be able to make Fuch sketches with such instruments as they are likely to laro on service. Theso instruments are i. The service comraes. it. The scrsice protractor 111. Tlie cavalry sketching board, or soinc improvised furn of sketcluing boord. 5. This manual 19 therefore duuded into tiro parts Part 1.--Tlic clementary instruction, embracing map reading and auch field sketcluing os 14 ltkely to be requirel of regimental oflicers and non-coinmissioned oflicers on activo service Part II --Further instructions in fickl sketching for officers who may be employed on thecual dury. CHAPTER II. DEFINITIONS. 6. Topographical forms Basin: A term used to describe (a) a small arca of level ground Burrounded or nearly surrounded by hills; and ) a district drained by a mer and its tnbutaries, as the "basin of the Thames." r. 191 st which a gentle blure changes to an abrupt ope; the top of a bluff or clili. Escarpment: An extended line of chals or bluffs. Gorge: A rugged and deep ravine. Knoll: A low detached hill. Plateau: An elevated plain, AVA or depression running into a main feature. Saddle: A col. Spur: A projection from the side of a bill or mountain running out Irom the main feature. Underfeature: A minor feature, an ollshoot of a main feature, ·9 Watercourse: The line defining the lowest part of a valley, whether occupied by a stream or not. Watershed: A ridge of lugh land separating tiro drainage basins; the summit of land from which water divides or flors in two directions. A watershed docs not necessarily include the highest points of a chain of mountains or range of bills. This list does not proſess to be exhaustive; there are many terms in common use such as bill, mountain, river, slope, island, pass, cliff, &c., which it does not appear necessary to definc. 7. Technical terms. Angle: Back-angle, the direction or bearing in a traverse of a station which has been passed. Closing-angle, the bearing taken from the last station in a traverse to some fixed point, to ascertain whether the traverso closes satisfactorily. Forward-angle, the forward direction or bearing from one station in a traverse to the next in succession, Base, or Base-line: A carefully chosen and accurately measured line upon which a triangulation depends. Bearing: True bearing is the angle a line makes with the true nurth line. Magnetic bearing is the angle a line makes with the magnetic north line. In each case the angle is measured from North by East and South, i.e., in the same direction as the hands of a watch move. Ray: A line drawn to represent the direction of an object without reference to the points of the compass Contour: The representation of an imaginary line running along the surface of the ground at the same height above meansea-level throughout its length Contours may also ho defined as the plans of the lines at which a trater surface of the ocean, for instance) would intersect the surface of the earth Tere it raised successively by equal amounts Datum, or Datum-level: An assumed level to which altitudes are referred. Fall of a river • Its slope, usually measured in inches (or feet) per mile, thus 9 inches per mile.

·10 Form-line: In approximate contour: & sketch contour. Gradient: a slose esped by a fraction. Thus x's represents a risc or all of l kol in 30 lect. Hachures: Vertical hacluring is a consentional method of representing hill features by Bladıng in slort disconnected lines elmin directly down the slopes in the direction of the low of saler on the sloper (See Platrs 3, 10, and 11 ) Horizontal Equivalent : fonetimes rritten II.r., is the distance in plan betireen two niljacent contours measured in yards. In his 1, S.L. 19 a klope, I1 E 19 the horizontal equivalent for that particular flore and vertical intersal (ore debation belos), Fu 1 F Local Magnetic Attraction: The deviation of the magnetic needle of a conpes imm its mean position orring to the presence land Fear. is E. Orienting or Setting a map or plane-table is the process of placing the map or plane-table so that the north live points north. Plotting: 'The process of laying down on paper field observations and measurements. Resection: A method by which the sketcher determines his. position by observing the bearings of, or drawing lines from, at least two previously fixed points.

·11 Section: The outline of tlie intersection of the surface of the ground by a vertical plıne. Spot Level: The record on a map of the exact leiglit of a particular point. Traverse: The survey of a road, river, or track by measuring a continuous series of straight lines along its course and the angles at their junctions. Triangulation: The process of fixing the position of points on the area to be surveyed, by means of a measured base and a network of triangles dependent on it. Vertical Interval: Sometimes written V I., and always given in feet, is the difference of level between two adjacent contours. L.F. in Fig. 1 is the vertical interval between contours at L. and S. CHAPTER III. SCALES. 8. The word scale is used to denote the proportion which a distance between any two points on a sketch or map bears to the horizontal distance between the same two points on the ground. Thus, if the distance between two farms on a map be 1 inch, and the horizontal distance on the ground be 2 miles, the scale of the map will be 1 inch to 2 miles. Similarly the statement that a map is on a scale of 76 opor implies that a distance of 1 inch on the map represents an actual distance of 250,000 inches, or 3.95 iniles. (1) Scales on maps of the United Kingdom, India, and Canada are usually expressed in words slowing the relation between incles on the map and miles on the ground, thus 1 inch to 1 mile, inch to I mile, &c. (2) Foreign maps and maps of British African Colonies and possessions are constructed on scales which bear the proportion of i to soine multiple of 10, such as 1 to 250,000 or 1 to 1,000,000. The scale adopted for the military map of South Africa is 1 to 230,000.

·10 Form-line: In approximate contour; a sketch contour. Gradient: A slope espressed by a fraction. Thus s'o represents a rise or fall of 1 fuot in 30 ſect. Hachures: Vertical liachuring is a conventional method of representing hill features by shading in sliort disconnected lines rawn directly down the slopes in the direction of the Bos of water on the slopes (See Plates 5, 10, and 11) Horizontal Equivalent: Sometimes mitten H.E, is the distanco in plan between two adjacent contours measured in yards. In Fig. 1, if S.L. 19 a blope, IT'E is the horizontal equivalent for that particular elore and crtical interval (see definition below). Fio 1 F H.E. Local Magnetic Attraction: The deviation of the magnetic Deedle of a compaes from its mean position owing to the presence of masses of magnetic iron ore or of iron in the peighbourhood, Meridian or Meridian-line: A true north and south line. Magnetic Meridián: A magnetic north and south line. Magnetic Variation: The angle betreen the true north and the magnetic portb. This angle vares slightly from year to fear, It is called E. or W. variation, according as the magnetic N. is E. or W. of the true N. Orienting or Setting a map or plane-table is the process of placing the map or plane-table so that the north ling points north. Plotting: The process of laying down on paper field observations and measurements, Resection: A method by which the sketcher determines bis position by observing the bearings of, or drawing lines from, at least two previously fixed points.

·11 Section: The outline of the intersection of the surface of the ground by a vertical pline. Spot Level: The record on a map of the cxact height of a particudar point. Traverse: The survey of a road, river, or track by measuring a continuous scries of straight lines along its course and the angles at their junctions. Triangulation: The process of fixing the position of points on the area to be survered, by means of a measured base and a network of triangles dependent on it. Vertical Interval: Sometimes written VI, and always given in feet, 19 the difference of level between two adjacent contours. L.F in Fig. 1 is the vertical interval between contours at L. and S. CHAPTER III. SCALES. 8. The word scale is used to denote the proportion which a distance between any two points on a sketch or map bears to the horizontal distance between the same two points on the ground. Thus, if the distance between two farms on a map be 1 inch, and the horizontal distance on the ground be 2 miles, the scale of the map will be 1 inch to 2 miles Similarly the statement that a map is on a scale of 50tor implies that a distance of 1 inch on the map represents an actual distance of 250,000 inches, or 3.95 miles, (1) Scales on maps of the United Kingdom, India, and Canada are usually expressed in words showing the relation between inclies on the map and miles on the ground, thus 1 inch to 1 mile, inch to 1 mile, &c. (2) Foreign maps and maps of British African Colonies and possessions are constructed on scales which bear the proportion 1 to como multiple of 10, such as 1 to 250,000 or 1 to 1,000,000. The scale adopted for the military map of South Africa 250,000.

·12 The following examples are esplanatory of the two methods of expressing scales (i) Scale aia, or 1 inch to I muile (11) 1:100.000 (or Too'sto), or on a Foreign map) 1 centimetro to 1 kilometre The fraction in ach case is called the Representative Fraction or R.F., and incans that l unit on the map mumerator) represents a certain number of the bune units on the ground (denominator), tlus from i above- 1 inch on the map represents 63,300 inches on tho ground (= 1 mile) fron 11 I inch on the map represents 100.000 inches on the ground (=1.58 miles), or 1 centimetro on the map represents 100,000 centimetres (= 1 kilometre) on the ground The advantage of (1) is that the eye, having once been trained to recognise the length of an inch on paper, can readily estimate the distance between any two points on a map with considerable accuracy To find the number of English miles to the inch for any map that has a RF, divide the denominator of the RF hy 63,360, this gives the number required thus af RF 18 raion, then the number of inules to the inch 388 = 1.26 To find the number of inches to the mile, divide 63,360 by the denominator of the R.F.. thus, If RF. 18 sito, then the number of inches to tlo mile = $= 79 9. The measure of length wbich a scale is to show, whether feet, yards or miles, is termed the unit of measure, nnd scales are usually, Though not necessarily, constructed of such n length as to represent a distance which is a multiple of ten such units, as 100 feet, 50 yards, 80 miles A scale should usually be from 4 to 6 inches long, and to construct it the number of tens, hundreds, or thousands of the unit of measure," which will occupy such a length on paper, should be calculated. 10 Tris cf. :---". 145.11-1-1.6 pagando naissance sketches of an area of ground to explain a plan of attack, or to show lines of advance, of a road or river, or of a defensive or

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·13 outpost position, are usually made on scales ranging from 1 to 4 inches to 1 mile. Sketches which may be required for the defence of a vllage or town, or for the selection of a camp or billeting area, are generally made oa the scale of 4 inches to 1 mile. 11. The service protractor (see Plate 14) shows scales of inch, 1 inch, 2 inches and 2 inches to 1 mile, also scales of miles for R F's. of totodtoo boo and door, and a scale of kilometres for To'opo (1 centimetre = 1 kilometie) Thus tho normal scales of English and foreign maps can be drawn from the protractor Example.- To draw a scale of 4 inches to 1 mile to show divisions of 100 yards from the protractor. Hero the most convenient scale shown on the protractor is that of 2 inches to 1 mile. The distances shown on this scale are twice those on the scale to be drawn. The scale is to be between 1 and 6 inches in length. On measuring off 4 inches from the scale of inches on the back of the protractor and applying this distance to the 2 inches to 1 mile scale, it is found that 4,000 yards as the nearest convenient round number, which gives a length of more than four inches, Drats a line equal in length to 4,000 yards on the 2 inches to 1 mile scale, this line represents 2,000 yards on the scale of 4 miles to 1 inch Divide this line into 4 equal parts, each representin ran 1. ITI.. 1. Ann from it. Primaries should be chosen so as to show miles or kilo metres 10 units, tens or hundreds, or yards, in thousands or five hundreds, according to the unit of measure shown and the size of the scale, Thus a scale of miles or kilometres should sbor primaries of miles or kilometres; a scale of yards or metres should show primaries of thousands of yards or metres for scales up to Tod, and five hundreds of yards or metres for Lrger scales. Secondaries should show miles, twentieths of kilometres, or hundreds of yards. Military sketches can rarely be of suficient accuracy to make it necessary to show smaller secondaries, these are botsever shown on the protractor, which may be used to measure distances on military maps.

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·15 or 5,000 X 36 Then 5,000 yards will be represented by 31,000 inches, 5.68 inclıes. Draw a line 5.68 inches long. Divide this into five equal parts (each being therefore 1.14 inch long). Subdivide the left division into 10 equal parts, each 0·11 inch long; each of these will represent one hundred yards. (Plate 1.) Ex. 3-To construct a scale of 1 inch to 1 mile to show miles and quarters of a mile. Here it is clear that all that has to be done is to take a length of say 6 inches representing 6 miles, divide this into inches and the leit division into quarters. Ex. 4.—To construct a scale of Tod'oro to show miles. Here 1 mile is represented by you soo mile. 63,360 inch = 0.634 inch. i e., by 100,000 ---- !f the whole onnino-mannon 1n mila i-ill L. 2.0:: - Ex. 5-To construct & scale of time for a column of troops marching at the rate of 3 miles an hour. As an example, the scale of the map may be taken as 1 inch to 2 miles, which gives 1 63,360 X2 120,720 If the scale be made 0 inches long, it will represent 12 miles, ie, ad euch 10n into 1 RF. 1 ·16 I Er. 6.--To construct & scala of miles for a foreign map on which no R.F. is given. (1) Sappose the map has a scale of rersts (I rerst = 42,000 isches) slion, Measure the leagth in inches of any pumber of verste, and say that 10 verste are found to measure 1 inch, then the 1 RF No of inches in 10 versts 420,00 40 x 1,760 X 36 40 miles will be represented by 420,000 0-03 eches. Draw a line 6.03 inches long and divide into 4 parts, uch will represent 10 mules, divide the left quarter into 10 to slow single miles. In the heading of the scale, after the IF, the pumber of miles to the inch should be stated. In this case 1 inch represents 420,000 13 Ches Therefore, the number of miles to the inch (see paza. 8) 420,000 663 63,363 (2) If neither the RF nor the scale be given, the distance on the ground between any two points shown on the map must be ascertaided, esther by reference to another map with a scale marked on it, or by actual measurement in the ground Suppose in this case that the distance bettreen two villages measures, on the map. 1.5 inch, and the actual distance betireen thern is ascertained to be 3,000 yards, then RF 3,60 x 36** 72,000 Since this is a smaller fraction than the RF: Costro) of 1 inch to the mile, the scale of the map is rather less than 1 unch ta tho mle If, therefore, we take 6 mies, the shall obtain a scale of suitable length. 6 x 1,760 X 36 6 miles will be represented by 72,000 = 5.28 inches. Draw a line 5.28 inches long and darsda it into parts, each of which will represent a mile. The left division may be subdivided to skont quarters of a mile.

·17 CHAPTER IV. COXTENTIOXAL SiGx9 AND LETTERING. Contentional signs. 13. Conventional signs enable the draughtsman to give an Amount of Information on sketch, or inap, which could not, con veniently, be otherwise conveyed. They should be simple in character, so that they may be easily understood, and not numerous. It is better to write descriptions on the face of a sketch, or in the at referred to in at with symbols 1 Plate 2 shows the conventional signs approved for field sketches. These signs should bo studied, and used in making a field sketch. In cases of great haste, however, it is sometimes more convenient to describo the object than to draw its symbol. The conventional signs used on Ordnance Survey maps differ slightly from those used in field sketching the latter being modified in some cases so that they may be simpler to draw. The conventional signs used on the 2 miles = 1 inch Ordnance Survey are shown on Plate 3 A Road is drawn with continuous lines when it is enclosed by a fence, ditclı, or obstacle of any kind, and with dotted lines when unenclosed. It should be noted thether a rond is metalled or unmetalled, and occasionally it is desirable to give its width. Thus Il' m. rould mean a rand the metalled portion of which is 14 feet wide. 14 feet of metalling will allow of two lines of traffic in opposite directions ; less than 14 feet will not. Metalled ronds suitab] for traffic at all times should be coloured brotn; those like' 21115 ·Ho est tip in burl weather dotted brown Il no colour is availa tlin Ford" matatiri," or "unmetalleil," and any additiopal ipfori tinn required should be inserted. A Railway 1x xlien la continuous, thick, black lines crrestara: thin sport "single," or "rouble," sbould be tritten alc it ng tio ca90 may lyn Opposite the point where a mun rond or railway stopped tho margin the name of the neareat important town or village slot bo written anrlnlu ile distance from that point in mles, Tu Canterlmuy smilen. Form Lincg and Heights are drawn in brosit or Form linea słould lo sloven by almost continuous lines, hrok Orcasionnity ly very slott spaces and dots where the hand requis regt. Cultivation us dennteel by inserting in writing the naturo the crops, Il they present any obstacle to the advance of troo or afford cover, a note to that effect should be added; but eu information Abould only to given if requircd by tho object of eketch. A River is drawn in blue, ssith its nano written along its cour and the direction of its current indicatel by an arrow, T width of thio tiver, and any further information ng to the botte and banks quired to slow its naturo as an obstacle should notcil on the sketch. Tho bod of a ricr or stream which is d nt the time of sketching should be shown in black, a note as its liability to lood keing made on the sketch. The nature of Bridge is indicated by the won iron, stay toood, stepentsion.de. Tho principal dimensions of important bruis and their suitability for beavy traffic should be stated. Heath, Heather, or Marsh is sloten by writing the you heath, heather, or marsh in black. When finishing up the lin !! contentional siga shown on the plate may boni, 1 liv permits. bodiats htated.

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·ORDNANCE SURVEY Plate 3 CONVENTIONAL SIGNS FOR THE HALF-INCH TO ONE MILE MAP OF GREAT BRITAIN Al lau Koduto Rolamay 22 ههههه Kined from uniwer 3rd Paivan ure Road Raul way of or fauvey Paksnort forms LAN W * CMEITA. WE Lerol tronna Mineral bonus Proxy Palese re Penly I WA Shalda ronal Railway AIVA Isotale R Rwers an Strumi Parfum Mart Ring our River ('n wandury W mich [online Br . I'ndapat Lewand l'ost fire P Poet of rol the 07 Trg Slot 14 Loullnet tors (Murchi of Bari Lt Hod Inghethemet Syrenk Trees Ruff Ranger w the oldes fins the floods are top sn Gm The kelio Pand l'indicating Vestond Tulegs oph Ofertas Jul rodiru in Chner forens thick trould thirrovitu kane # t or Telegraph fire thrine Survey diline ampton ·19 The conventional colours are shown on Plate 2. For rough sketches, coloured chalk pencils may be used. Troops.-It may be necessary to show the disposition of troops on a sketch, as, for instance, when making proposals for the distribution and action of a given force It is not desirable to spend time in drawing troops in any form to scale. It is sufficient to draw a symbol which will attract the attention, writing the necessary information as regards strength and unit alongside or in the margin In outpost sketches, the letters P, S, R, may be written instead of piquet, support, and reserve. The direction of a patrol is shown by an arrow. Lettering. 14. Whatever lettering appears on a sketch must be easily legible, should not interfere with the detail, and should show clearly to what it refers. These are the only essential conditions. It is within the power of all officers to adopt and use some simple style of lettering which shall be clear, and quickly written, Each letter should be separate. The principal ords, ie, names of towns, villages, and rivers should be in simple block letters (Sce Plate 2.) All lettering should be horizontal, excepting the names and directions of rivers, railways, roads, and canals, which should be written along them; words descriptive of the nature and condition of a tract of country should be written so as to, as far as possible, extend over the portion of ground describedl.

·CHAPTER V BRITISI ANT) FOREIGN DLARS, AND METTIODS OF REPRESENTING WILL FEATLNES, 15. The cluef difficulty felt by most students in reading maps is in understanding the methods used to represent bill features. These consist of various artifices by means of which tho inequalities of the ground are shown. The following systems are employed for showing hill features on maps: 1. Contours, or approximate contours, ie, form lines. 2. Contours and hachuring, ie, shading 3. Hachuring alone 4. Layer system (altitude tints). Plates 7, 8 and 9, show maps in which bill features are represented by contours. Plate 5 shows maps representing hill features by contours and lzachuring combined. Plates 10 and 11 show hachuring alone. Plates 6 and 12 shos maps in which the hill features are represented by the layer system. 16. Contours.-These are best explained by the following simple practical illustrations All students will be familiar with the ordinary wooden or plaster models sometimes used to represent in relief hills and other geographical features. Say we have such a model, the scale of which we know to be t's, ie, one inch on the model represents one foot on the ground. We place the model in an empty tank or bath, and pour in water until there is one inch of water in the bath.

·21
The watermark will cut the model one inch rertically above its
base, all round We dry in this waterpark with an indelible pencil.
We now add water until there are two inches in the bath, and
the new watermark is drawn in.
We continue to add water by inches in this way, and to draw in
the successive watermarks, until the model is completely covered
with water.
FIG 2
View of a lull with contours supposed to be visibly marked.
400
400
300
300
200
200
100
100
1001
200
300
400K
100 300 200
100
Plan of the same buil
On removing the model we find it marked with a succession of
lines, which we know are sertically one inch above the other.
These lines are " Contours."

·21 Sot if we make a cinsing of thic molel as seen froin above, i c.. a "plan" of the model to the actual scale, we shall have marked on it "Contours" at ono inch vertical interval --or in other sords, we have a map of the actual ground, on the scale of 's with "Contours" at one foot vertical interval In practice, for ordinary scales, " Contours " t so close an interval as one foot would be too numerous. The interval bet rrecn the "Contours" depends generalls on the scale. Fig 2 gives the icts of a hill with " Contours" 100' apart. 17. Contours have certain advantages for the map reader over other artifices, viz. i. They show the hill forms with exactness, and not vaguely, as as the case with shading. ii. They require httlo artistic talent to draw. ii. They obscure the detail less iv. They can be reproduced by lithography in the field, They present, howerer, a disadvantago to the map maker, in that the methods required to produce them involve frest labour and consequently expense This erplains why only the best maps are contoured, and then only at considerable interval of height. In view of these adrantages 'and disadvantages as regards contours, a hind of compromise 18 adopted for Field Sketching, and the metliod of showing hill features to be used is that of form-lines which are approximate to contours sketched in by eye. 18. Certain points sliould be noticed by the student as regards the information conveyed by contours or form-lines. Thus:- i. If a map shows contours close together, the slope there will be steeper than in places where the contours appear furtlier apart. In Fig. 3, plan, the ground is steeper at A B tuin at CD. This is at once apparent if sections be drawn as follots ;- Draw equidistant sod parallel dotted lines equal in ·23 300 to corressond to the remaining contours. Marka dot b on the lowest dotted line to represent tlio point here the section lino A B cuts the 100 contour in plan. From b, measure off bc, = b c in the plan. At c, drave €,c perpendicular to the 100 dotted line, so as to cut tho 200° dotted line at c Then measure baba in the plan, and draw a, a similarly to cut the 300 dotted Drawy the line Aaco B in the section. The line C D is similarly drawn, and the slopes A B and CD can be compared. Section drawing of this nature is purely for instructional purposes and has no practical value line at a 116 3. PLAN 300- А 300 200 200 - loo too B D SECTION soof 500 200 1200 100L -100 D B ii. When contours bend they portray a spur or projection; or they portray a valley or re entrant. To ascertain ·mbich, the numbering of successiva contours must be ennined if there is no distinctive sliding in addition to contours. In Fig. 4, reading the contours down from 300 fect to 100 fect, and imagining them mised on uprights to scale corresponding to thiese heights, the bend A B is seen at orice to be a spur, tbe bend CD a ralley. iii. Referring to Plate 4, slopes may le uniform, like 1 B, convex, libe C D, or concave, like E F. Xom, it contoure le dratto in plan to represent a short distance of these slopes it till be apparent that their spacing in each case is stinctne of the particular kind of slopo representeu, us follons - 1. When the contours are evenly spuced as in plan (1) the slope represented is uniform. ii When the spacing, rearling from bigh to low, decreases, as in plan (2), the slope is convex m. When the spacing, reading from bigh to low, increases, as in plan (3), the slope is concave. It may be noticed that unsform and concare slopes, (1) and (3). FIG A 300 100 200 200 Ibo 300 afford no dead ground Conrex slopes (?), on the other Land, do afford dead ground. 19. Slopes may be expressed either in degrees or as a gradient. Slopes are usually expressed in military terms as a gradient, ie, by a inactica-Thus z's represents a rise or fall of 1 foot in 30 feet.

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·SEC
(1) Uniform
(21 Co
100
90
80
70
60
50
B
F
(1) Uniform.
(2) Co
001
OG
09
001 -
06-
A
8
21173

·--
Pi.TC 1.
2. fucc pur 21
10NS.
ivex.
(3) Concave
E
100
90
80
70
60
50
---
D
F
PLANS
vex
.(3) Concave
D.
F

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·05 ' a slope given in 'hus a slope of 30 • This rule does not hold for steep slopes 20. The following slopes are generally practicable for wheeled vehicles, but much depends upon the surface of the ground. For short distances the slope may be for artillery, I's for transport animals. Stecher than to is inconvenient for animals or wheeled traffic Traction engines can draw their own weight up to, twice their weight up , three times their weight on the level or up slopes not exceeding is (For the method of measuring slopes, see 1 >1 3 para. 54.) 21, The student should exercise himself in studying the system of contours as a means of depicting hill features. Ho should imagine some type of ground with various combinations of spur, valley, and slope, and then endeavour to portray these by contours. Conversely, he should draw contours with various curves and spacing, number these successively, and work out the ground they represent Such preliminary exercises will greatly assist him to read bull features un contoured maps fully, rapidly, and with accuracy. CHAPTER VI. COPYING AND EXLANGING Mars. 22. Copying:—Maps which are to be simply copied without reduction or enlargeinent, may be first traced on tracing paper, and then, a piece of carbon paper being placed Lettreen the tracing and a clean sheet of paper and both very firmly fastened down by drawing pins, the tracing may be transferred by following the lines with a pointed instrument.

·26 carbon puser can be made of tracing paper, in fact, Any slarp piece of rood will do for tho tracing instrument. A map may also be transferred direct without a tracing; but there is somo danger of daimaging the enginal with the point, Tracing cloth is useful for copying It is tough and will lear much handling Draw on the glazed side, and put washes of water colour, If required, on the back, darker than they are intended to appear on tlie front 23. Enlarging.- \l licn it is required to enlarge a inap, squarch of any convenient size aday be drawn on the origina), and the paper on su luch the new map is to be made ruled with squares whose sides bear the required ratío to the sides of the squares on tho original. Tho original is then copied by efe, so that objects occupy the same positions relatively to the squares as they did in the original (Scc Fig. 5.) Ex. 1.-It is required to enlarge to 4 inches to 1 wurle a map of which the scale is incl to 1 mile. Squares, inch sides, are down on the map "Then to find the length of sides of squares on the enlargement, we have :-- $.4: : Length required. Whence sides'of squares required = 2 inches, Ex. 2-A plan with R.F. soo'spo is to be copied at 4 inches to a mile. Squares, inclı sides, are drawn on the plan. The R.F. of 4 inches to 1 mile being made, the length of sides of squares on the copy is obtained by proportion, thus: 1 Toot : 7 : 1. Length required Whence required side of square = 1.58 jpcles. Anny Book 163 and most service pocket books contain paper ruled in quarter-inch squares. When such paper is available, it is usually only necessary to rule squares on the map which is to be enlarged.

·27
FIG. 5 (1).
hesh
Portion of "12" ntap of England
FIG. 5 (1)
Hawkesbury
Longford
Enlargement i laches to 1 mile.

·Girls degree and thio points of the compass (sce Plate 13) The socta! cuser, C, opens ou 3 lunge, and is fitted with a glazed stindow, W', on which is traced a finc black hair line, V, for use as a sighting-vane. Opposite thic bingo of the coser 19 fitted 2 prism, R, through which cin be read the graduated edge of tho dal, while at the same time an algubient f the olyzect ant vf the sight-rane on the cover 13 observed through the shit out The វរSin should be moved up or down in its nlnt till the figures on the iss are properly fexcussed A clamping-screw, S, is provided for clapping the needle when not in use, and a check spring, for keeking its oscillations when observ- 108 Abrrss ring, I, is attached for convenience in holding it. Tbo dial 19 "lumanus" for night rork, the north point 19 marked with a lirgs dramond-shaped figure revolving glass is fitted over the conspiss dial, and on the glass is a black direction mark, radiating from the centre, at the end of wbich is a small brass "setting vane," the latter working over an external arc graduated to 360° A brass surew, J, 18 used to clamp tho glass. On the inside of the cover ore tuo luminous patches, PP, which gire a good alignment of the instrument at night seen it is held in the hand with the cover wie open There are to small holes, AH, in the brase window-edge of the cover, so that, of the glass breaks, a borse-hair can be run between them, and an extemporized sightyine betalized. The compass dul is graduated with two sets of figures which read easture of the meridian (scc definition, Chapter II), or from left to riglat, Ithe tbe hands of a watch The outer set 13 for use with the prism, and commences at soutb sa order that the bearing of the object my appear under the eye. Thus the rane being directed on an object which 15 50% from north, it is that number measured from south which appears under the prism; or, in other words, 180° is over the north end and 360* over the south end of the needle. The inner set of figures is of use for direct reading (ie, without the prism) es for compass marching, or when the instrument is used with the plane-table, The prismatic compass gives " bearings" Rad not "angles" (see. defnitions, Chapter 11). The horizontal angles bet treen any distant objectsbreobtained by taking the differenceof their obserred bearings. Example.The anglo bestseen tro points. Å and B, is required. Their bearings are observed to be respectively 50° aad 110º. The angle required 110 50 60°,

·H
'N
W
PRISMATIC COMPASS

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·31 27. (a) to use the compass as a hanil compas. Tlold the compass level in the hand, or place it on a level surface; when tlie card comes to rest. The clicck spring can be used to steads the sking of the card 50 that it muy more rapidly come to rest The graduation of the inner ring of figures, immedintels under the under line, gwes the magnetic bearing. (b) is a prismatic compass. In order to obtain the bearing of a distant point, the observer directs the sighting vane of the compass on the object and reads its magnetic bearing in the prism (c). As a night marching compa88. - 28. Marching on a Compass Bearing:--To use a compass with advantage on a dark night, it is essential that it should be prepared with "luminous paint' This substance must be kept exposed to the light before using it, or it will be found to be non-luminous when required. As a general rule, compass erposcel for half an hour before sunset will be sufficiently luminous to work by for some 6 to 9 hours afterwards. In the Service prismatic compass the magnetic north is marked by a broad black arrow-head. The compass 1s Bo constricted that upon the black direction mark being turned to point to the required "bearing." as shown on the external sing, and the arrow-head 1. MannnnA with ha hlint durantinn er 1 i.. pected from luminous paint is for a compass prepared with it to slow a faint luminosity of the dial, just sufficient to throw up in relief the black direction mark and arrow-head. 1-- LL. l. wate. L. inarked north point.

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·33 31. The Service Protractor (Plate 14). The service protractor for sketching is made of borrood exactly 6 inches in length and 2 inches in breadth, it is divided on botlı sides as shown on Plate 14. On it four scales of yards are shown 21 inches to one mile. 2 3 ta IT 15 3 33 31 3) on these scales the primary divisions show hundreds of yards. Three scales of miles are shown - 1 80,000 or 1 inch to 1.26 miles. 1 100,000 " » 1.58 19 1 250,000 3.91 1 One scale of kilometres The edge graduated in degrees is for reading and plotting angles, the arrow point showing the centre from which the angles are drawn. 100,000 13 also shown. 32. Plotting and reading angles. The direction of an object observed with the compass, expressed in degrees from the magnetic north measured round up to 360° with ibe bands of a ratch, is the beanng of the object, and can be laid down or plotted on a map or sketch sith a protractor from the point of observation In plotting angles, if these angles are magnetic bearings, and if it is required to plot any line must be drawn throuç In practice it is pot neces this meridian through eve is taken. Starting from 80 is Grst drawn, and then a 20175

·fatter serve as a general guide for placiag w protractor on any
point after rarily in the correct position. One of them wl be
merr enough to the point to guide the eye.
FiG 1
TO OL
'B
AN
TO OL
Note--la abore figure the protractor 15 ansiuied when in position for
plotting beings between 1800 and 3G04.
It is usual to drait these parallel lines representing magnetic
meridians about the width of the protractor apart. The proprietor

·35 can always be set with its long edge parallel to theso lines, by making one of the lines cut each of the shorter edges at opposite and similar divisions, or by eye. One end of these meridians should be marked with an arrowhead.to avoid the possibility of protracting the bearings in the reverse direction. The protractor is laid on the map or sketch with the arrow at the point whence the bearing is to be drawn, and with its long edges set north and south, z e, parallel to the lines. If the bearing is under 180°, the graduated edge of the protractor is laid to the right or east, if over 180°, to the left or west, the north margin of the sketch being uppermost. The bearings of the various points in Fig 7 are read thus C, 3° [F, 181° D. 40° 15' G, 220° 13 IL, 66° 15' E, 60° I, 2320 At AB, 8.50 47 At BA, 231° 45' F, ilvº C, 309° 15, 2120 0,3349 D, 3150 ( II, 171' 309 E, 317° At F-C, 32215' To plot the bearings taken from A tho protractor is adjusted witlı its centre at this point and its graduated edge to the east. The positions of all the bearings under 180° are marked off, and fine lines of indefinite length drawn through them from A, as shown; thoso over 180', if any, would nert be protracted The point at which the bearing is to be laid down may Le so near the edge of the paper that the graduated edge is off 1. In tlus case lay the protractor with the graduated edge inwards, and produco the required bearing outwards through the centre At GK, 309 At DL, 1209 33. The bearing from one point to anotlier on a map or sketch may be read by means of the protractor as follows:--If the true bearing is required, a meridian, or line parallel to the true north and south line, must be down through the initial point; if the . C?

·36 map cuts the graduated edge of the protractor gires the reading in degrees If it is necessary to lay the graduated edge to the right or cast, in order that the line betrreen the two points may cut it, then 34. True and magnetic bearings (Sre definitions, Chapter II) Sometimes one of these is given and it is required to convert it 18 the variation as tle case may orders true bearings are given The reason for this is that most omn, due to imperfections of manufacture, independent of the magnetic variation It is, therefore, necessary to ascertain the exact variation of a compass when it is first obtained and to check the variation periodically. 1 as describeu in para. 34. The umerence between luo uue suu the magnetic bearings gives the variation of the compass. 35. The beginner may be puzzled in converting true into magnetic bearings or in finding the variation of the compass unless he draws a figure. Examples (1) The variation of the compass is 13º West. The magnetic bearing of a point Pis 29º. What is the true bearing? First drait

·37
a circle and mark on it the known facts, 1 c., the position of the
true and magnetic N. Ponuts, thus .-
FIG b.
As the bearing given of the point is a magnetic bearing, lay the
protractor with the airow-head at the centre of the circle and its
edge along the magnetic N line Then measure off 29° to the east
and mark in the point P
FIG 9
The position of T with relation to the true N. can then be read off
V12 29-13° 10°
(?) True learing A to B 13 227º. Variation of compas, is 10° E.
What is the munguctic bearing of B from A? Proceed as in
Example (1).

·38 First draw the circle, put in the true and nagnetic north. Then measuro of 227* from the true north live, thus gives the position FIG 10 B of B The magnetic bearing of B from A can then be seen to be 227-10º=2170. (3) The true bearing of a point P is 250°, the magnetic bearing of the same point 13 205º. What is the variation of the compass ? FIG 11. 2os Draw the circle and the true north line. Thien ineasure off froin the true north Line the true bearing of P. i.e., 250°, Dark in P. Now start from and measure off 265' from west to east, ic, lay the

·39
protractor along the line from the centre of the circle to P. with.
1
i
the left or trest of the true north, the variation is 13 iv.
(4) You wish to find from an Ordnance map the magnetic bearing
of a point B from a point A Variation of compass is 164 W.
FIG 12.
Join the two points by a pencil line. Through A draw in pencil
true and magnetic N Points Measuro mrith the protractor the
angle (by E and S) between the magnetic N. and B.
F10. 13

·40 CILATTER 1711 ATPROSATE ALETHOD OF FINDING THE Tnpe Sorti. 36. i With a compass, if the magnetic nation, skich can be obtained approximately from Plate 13, 1s known. 13. In the northern hemisphese, in ordinary latitudes, the true bearing of the Pole Star is always tathin 2 of north fis. In the southern kemisphere the Southern Cross may be used as follors Consider the Southern Closs as a kite, prolong the greater axis 45 times in the direction of the tail, and the point reached will be approximately the South Pole of the heavens If a piece of paper de narked off long its edge by twelve dividrug lizes giving eleven equal divisions and be beld so that the first and third divisions concide with the lead and tail stars respectively, the intersection of the twelfth line and the edge of the paper mill give the approImate south post. iv. At the equinoxes (end of March and end of September) the aun rises due east and sets due west. v. At apparent noon the sun is on the meridian Apprent noon may, however, differ from mean local noon (12 o'clock by a watch) by as much as 10 montes Moreover most countries now keep standard time of some pastscular mendian for use in railways and telegraphs throughout the country so that the time in actual use may differ considerably from the mean local time. At noon by the watch the sun may be a considerable amount off the meridian. vi. In the Northern Hemisphere --Hold the watch horizontally with the fare upward. Point the bour hand at the sun Then a line from the centre of the dial to a point halfway between the figure XII and the pointer of the hour band is approximately a south line. In the Southern Hemisphere -Holt the watch as before, but in this case point the line from the centre of the dial to figure XIL at the sun, then the line found 19 above is in this case approximately a porta lige

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·CHAPTER 171 APPROXIMATE METHODS OF FINDING TUE TACE Xorn. 36. i With 3 compass if tłe mignetic variation, which can be obtained approumately from Plate 13, is known 1 In the northern hemisphere, in ordinary latitudes, the true bearing of the Pole Star 18 alırays within 2° of north. 1 In the southern hemisphere the Southern Cross inay be used as follows -Cossider the Southern Cross its a kite, prolong the greiter axta 43 times in the dissection of the tail, and the point retched will be approximately the South Pole of the heavens. If a psecc paper be parked off along its exige by twelve di riding lines giving eleven equal disissons and he teld so that the first and third divisions coincide uk the head and tail stars respectively, the intersection of the twelfth line and the edge of the paper sill give the approximate south point iv. At the equinoses (end of March and end of September) the sun rises due east and sets due test. v. At apparent noon the sun is on the meridian. Apparent noon may, however, differ from mean locul noon (12 o'clock by a watch) by as much as 16 minutes Moreover most countries now keep standard time of some particular mersduun for use in railtrais and telegraphs throughout the country so that the tsme in actual use may deber considerably from the mean local time. At noon by thie watch the aun may be a considerable amount of the meridian. vi. In the Northern Hemisphere. Hold the watch horizontally with the face upward. Point the hour hand at the sun. Then a Hide from the centre of the dial to a point hallmar betrpeen the figure XII and the pointer of the hour hand is approximately south line. In the Southern Hentispliere...Hold the match as before, but in this case point the line from the centre of the dial to figure XII at the sua, then the line fouad 29 above is in this case approumately a north line.

·C VARIATIOX. 1912.
the
E IN MIXTES OF Alte
To fue por
1
oso
170
IAD
INO
T

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·41 This method is a very rough one. It should never be used in the tropics, and the higher the altitude, 1.c., the further from the equator, the more reliable it is. NOTE -- None of the methods given in para. 36 is to be used for determining the magnetic variation (see para, 34). CHAPTER IX. MIAP READING. 37. Proficiency in map reading is attained swhen the study of a good map enables the student to visualize in imagination the country portrayed Maps vary greatly in style of reproduction, and in the annount of information they convey. Notwithstanding their great military uses, they have their limitations, and sbould never be considered a complete substitute for the examination of the country itself. As already explained, dependence on active service will lave to be placed on maps of small scale The smaller the scale the less completely can a country be portrayed in detail. Even with the best large scale maps, valuable military information as to the form of the ground, more particularly as regards underſeatures, may often not appear Generally speaking, inaps are more lacking in complete information as regards form than as to detail. The expense of close contouring being prolubitive, it would be exceptional to get a 6-inch map contoured at 20 fcet vertical intervals Even were it so contoured, such a map could not be used in substitution for a visit to the ground to determine exactly where a firing line could best, be placed, or precisely what concealment the ground in particularly the case with gently undulating country, and snak ronds. It will, therefore, be seen that maps are an aid to, pot a substitute for, tho study of the country itself. 38. On taking up a map, look at once for the scale: this is the key to distances. Then carefully cramine the hcights and the ·incthod of slowing the form of the ground with contoured maps (tlie most useful) tlie vertical intervals used slvuld be noted, as well as spot levels that may indicate under-features. Some maps show only spot levels. These will be found generally on the heights, along main rauds, along railsavs, at villages and sometimes in valleys and other situations. This method of scattered lerels is generally combined with a petoria) method of shading Plate 5 shows contours, vertical Lachuring, and spot levels Plates 6 and 12 show maps on the laser system Plate 10 stints a German map. Phate il a French map, with spot levels and sertical hachures. The heights in both cases ITC shown in metres (Scales of kilometres altered to shos miles) 39. A failing in many uncontonsed maps is the sparte number of levels given in valleys, or at the foot of billa, the top of hills are 40. An important item to look for on a map is the direction of true or of magnetic north In all descriptions made with reference to a map, the points or degrees of the compass are used to express the direction of one object from another In the small scale maps of the Ordnance Survey the sheet-line margins are rectangular and are dmin parallel to a central meridian. For sheets through thich this meridian passes the marginal lines are nearly true north ani south, with the north towards the top of the sheet; but for sheets to the east and test the margins deviate from the true north, the maximum deviation, however, in the extreme east and west counties is not more than 4° east or west respectively Where 1 4... Sec 9, vii) 41. A nap is said to be "set" when it is laid out ta correspond with the ground, so that the true north on the map points to the North Pole If the directions bet reen features on the ground Le now compared with tliesc directions as shown on the map they will be seen to be parallel.

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·a on A and draw a line towards yourself, then align the ruler through b on B and draw a line towards yourself. The intersection of these lines z is your position. This process is called resection (see definition, Chapter II), and is of the greatest use both in map reading and in sketching, for by means of it an observer can find his position from two known points. The servico prismatic compass can be used for resection as follows (sec Fig. 14): FIG. 14 A IB 6 ---- An observer standing at & identifies two points a and b, which taken from the observer's position at the stations identitieu vu lue map or sketch with the protractor reversed, ie, turned to left or west for bearings under 180°, and to the right or cast for bearings over 180º.

·canal, &c, and one point can be ulenthed in the country to cha Then it A and B be to points on the ground in line with a observer's position, identified 38 a and b on the map, and be a point on the ground on one side of A 1, identified as c on the way align the ruler through con C and draw a line towards yourse various mithryly and arufiring Ulu Inakin maps, the studer: 43. Hap Reading on the Ground. Having mastered the should thin stond from ano bih pet of observation com Jare large on all male maps trith the ground. Two methods fullu in drail for botne time, say, 1 I do the p2p, tise Bear s: asd from your posts in dirir of rolls $:: 1998, IT LE2, E**7 eligen, mit 1. form of 1! Tyrred on the cap. In fixing a position by resection, the angle made breedte section (a 2b, Fig. 14) should not be too obtuso or to act. ic angle should not be greater than 130° or less than 50° if the Rain is to be accurate. it. When your position can be identificil as in line with known points or on a given straight line, such as a rad. ita side of the given line, set the map Fio 10 . 6 the interaction of this line with a b at 7. flies your position. of etarly bol.1 tx: alu-talu; C " ok at the count IT'S Arm1., t, ac ·46 ii. Mare a good look at the country first. Estimate distances and heights. In your mun convert distance into incles according ou erpect what the 44. In the above ererciseg, a) errors made should be carefully thought out More will be learnt by systematically working the mind and imagination than by immediately looking from the ground to the map, or vico versi. Moreorer, the second erercise of visualizing the map from the ground excellent training for sketching The above exercises should be carried out with both lirge and small scalo maps for the same country. It is instructive, for instance, to compare on the ground a 1-inch map with a 4-inch inap 45. Small scalo maps, eg, t-inch, are apt to puzzle the beginner in a country so full of detail as Englınd. Nach detail is necessarily omitted on such a map. Thus, in tmvcrsing a road, ho may find small by-roads omitted, and feel puzzled because he cannot estimate bis progress by merely counting each turning met with. It is a help to check oneself by time as a measure of distance. If the map shows the next cross road a milo ( inch) ahead, it will take about 20 minutes to talk so if a cross-road 13 met with in 10 minutes, it may safely be considered to be some road other than the one on the map. Again, short but decided 2.-..-.- nun and pham... wil onorog and hand streams it appears that the ground falls generally in a N.N.W. direction totvards Beckford. Just S E. of Osenton Hill is a detacbed knoll marked 531, and a spur rung out from this knoll in a direction slightly east of north. From the course of the stream, which passes by the of Gretton Field, it may be assumed that this spur passes through the copse marked just south of the n in Alstone, and ·ends in the sharp bend in the river south of the 8 in Little Washbourne West of tliis spur there is obviously a re-entrant, with its head at the col connecting knoll 531 with Oxenton Hill, and it 1 1 1 1.- In. 11 There is clearly a spur running N.N . Irom Alstone towards Beckford dividing the Little Washbourne stream from the next small stream to the rest Thus, though this ground is shown by an even wash of colour, the map clearly indicates that it consists of a series of spurs and re-entrants, and not of one even slope If the reading of small scale maps be practised in this manner, they will be found to contain a mass of information which is not apparent to the untrained eye. 46. It is occasionally useful to ascertain from a map whether certain points shown on it are mutually visible on the ground. The best methods of doing this are given in Appendix IV. CHAPTER X GENERAL PRINCIPLES OF SKETCHING. 47. The essentials of a military sketch are It must be relevant to the object for which it is undertaken. i It must be clear and legible. iii It must be completed in time to be of use. iv. It must be as accurate as circumstances permit. 48. The main principles shich underly all map-making, from the most accurate survey to the roughest sketching, are the same. Let us suppose that a representation on paper is required of a given piece of country. It is obtained by first " fixing" on the paper to a Riven scalo the relative positions of a certain number of points on the ground, and thus constructing a framework or skeleton on thich TTC can "lang" the details that lic between the points. These details are fillel in subscquently by rougher methods.

·48 Bpires, &c The selection of these points of the frame trork, or "ruling points," as they are called, is the primary stage in the construction of tho map of sketch. They will be points thich are most clearly defined on the ground, such as hill-tops, tall trees, church The distance apart of the ruling points, will depend on the type of the map being constructed, but for sketching purposes it may be taken that all conspicuous well-defined features will be utilized as ruling points-the more that can be “fixed” the better, the idea ance is there eye of the two traversing. 49. Triangulation. In this method we consider our ruling points as making up a series of triangles Say we have four ruling points-A, B, C, D, -... dhewe 1 FIG 16. 8 с D A D Where C is visible both from A and B, and D from A and C. If yo measure A B on the ground, and by some means or other observe the oneinn Annin alat A B to any given scale, position of c. e anglas D A Cand length AC on the d on the paper), fix ·49 11 TA the position of D; so it is seen that, by measuring one distance between two giren points and taking cogles from the various points to each other, tre an fix the position of any number of ruling points. The measured distance, in this case A B, is known as the "base," and the points fixed by taking angles are known as "intersected stations or simply " Intersections herwise the "rays angle." To obtain as possible, 50. The usual method of measuring distances, such as the base AB, is by pricing The beginner before starting work should pace some known distance several times so as to ascertain the number of paces he takes to, say, 100 yards With a little practice a man of ordinary build can ncquire the habit of pacing ya with safficient accuracy for practical purposes. 51. Rays may be taken either with a ruler (straight edge) or with the prismatic coin pass. The former method is the simplest and quickest, and 19 sufliciently accurate for such field sketching as is required of the regimental officer The ruler is piroted on the point from which the observation is to bo taken, say À (Fig. 16), and then aligned on the ruling point which it is desired to fis, say B. A line is then drawn from 1 to B In fixing the position of A on the paper it is necessary to consider the general shape of the area to be sketched. This may be done either by examining a map or by looking at the gipund. The position A is then chosen so as to bring the whole of the area on to the paper As soon as the ray A B is drawn a compass should be placed on the paper, while the ruler 19 still pointing from A to B, and the magnetic north linc be marhed on the paper. In taking all future mys the sketch should first be set as described in para. 41. Rars are then taken from A to Dand C, the other 1xsible ruling points. Wo then proceed to B, which is fixed by pacing, and after setting the sketch take a may to C. The intersection of the mys A O and 1) Ciscs C. In practice it is not necessary to dos continuous raya. It is sufficient to mark the intersection. To obtain good intersections the angles made by the rara skoukl 1o ltiseen the same limits as in ·50 Teseeting (pam 42), jc., betteen 50° and 130. A3 soon as tro or more ruling points liase lx en fired, other joints from which such ruling pinto ire i7sible may be firal by resection as described in para. 42. 52. Intersections and resections may be made by nicans of the prismatic compass, bearings being taken as described in rara 27, and plotted as described in pura. 32. Tlis methol is usually more accurate than the method of taking rays with a ruler, but is much loner. Fis 1. 31, show a base 1 B and stations C, D, C, F, G, H, I, K, fixed by intersection 53. Traversing.--This method till usually bo confined to cases where the ruling points are not niutually visible, cn. in bush country, anil so the trungulation method of intersections is not Tuossible. It is also muro suitablo Then the sketch is one of a route,"19, a road sketch, mther than of an "arca." Say to have three points ABC(TR. 17) which tre mi-l to fix ivo can seo В from A, and from B, but not from a la is not Fig 13. B already a fixed point on the sketch tre plet it in any convenient by some means or other, and measure the distince I B. Jf tre plot the direction on the rir, and ineasure of the clistance i B to scale, tre bure the position of R. We can then proceed in a similar manner to fix C.

·CHAPTER XI. SKETCHING WITH A CAVALRY SKETCH.C BOARD. 54. The cavalry, sketching board is a small board which can be straprel to the fole-arm. A magnetic compass is fixed in the board. Two nollers on opposite sides of the board enable a long strip of paper 75 inches wade to be carried, the paper being unwound from one roller and wound up on the other as the sketch proceeds. The rollers can be clamped by rotating their ends in the direction noted on the board The compass is fitted into a circular metal collar in which it Terolves A fine inder line is marked across the glass, which can be adjusted to any required position by turning the class. Before commencing to sketch it should be so adjusted that when the index line coincides with the needle, the direction of the paper is that of the general direction of the route to be followed. On the back of the board is a clinometer graduated to 50° and protected by a sheet of celluloid In order to measure any slope the board is lield upriglit twith its straight end parallel to thio Blope, and the clinometer 13 freed hy piessing the knob On relasing the pressure, the clinometer is clamped and the slope can tlıcn be rend oli. 55. The cavalry sketching board is suitable for mounted or dismounted sketching On lorseback it should be strapped to the left arm, midway between elbow and wist. The left hand (the bridle land) should be kept high, to prevent the board from knocking on the pommel of the saddle. When sketching on foot the straps should be held firmly in the left band, which should be close up to the back of the board, so that the bourd may be revoli ed on the forefinger and tlumd. 56. Setting the Compass. Before startiog work the compass should be "ct" 60 that the direction of the road runs generally up the length of the paper. The general direction of the route may sometimes be seen from the starting point. If not, its magnetic bearing may be giren, or its true beariog may lie taken froio a map. 2 ·i. When the direction is seen -Turn the board so that the "line of direction” marked on it points along the direction of the route Holding the board steady, more the line marked on the cover of the compass until the knob end is over the north point of the needle 11. When the magnetic bearing is given.--At first ignore the needle Put the line on the compass cover on the line of direction," the knob end totcards the roller containing the sketching paper to be unrolled when at work; then turn the knob backwards (ie, by west) through an angle equal to the bearing given Then when the board is turnect until the knob end of the line on the cover of the compass is over the north end of the necdlc, it is set This may be explained by means of a diagram as follotrs.-- FIG 18. B Here A B is the line of direction on the board. the circle represents the compass and C D the movable lipe on the cover, with the ·53 knob end at C Suppose the magaetic bearing given as the general direction to be followed be 40° whenever the board 13 set, the bea 40'. To do this we move the line with the line of direction A B with the knob pointing the way we wish to go. Then we move the knob end of the line 40' to the west, or in the reverse direction to the readings of the compass. Now whenever the board 19 turned so that the magnetic needle coincides with the line CD, the north point of the needle being under the knob C, C becomes the magnetic north and the bearing of the line of direction A B becomes 40°, which is what we want. If in the course of the work the sketch runs off the paper, sketch. 57. The following rules should be obscrved when aketching, either mounted or dismounted, with the cavalry sketching board :- i Turn the house, or body if dismounted, in the direction of the object ii. Revolve the board until it is "set" by the compass. in By moving the left arm or hand to the right or left, bring the 5 array from you It is well to take a second look at the Any elight alteration of the position of the board, in order to obtain a more exact cunculence of the needle and the index line, is best accomplished at this juncture by gently turning the left wrist ani forcarın. The currect alignment of the ruler on any distant point is a multer of judguent and “ce." With a little practice the ruler cau lo aligned, and thig dirertion drawn in, correct to within 90 or 30, in between 10 and 20 seconds Most horsey soon get accustomed to the work, and will stand s!cady enough for a brief period immediately after beiog reined up ·51 After a little practice the ruler can be dispensed withi, except for long "shots," and the directions of objects drawn in by placing the pencil point at the place representing the position of the obserier and drawing a line in the required direction. 58. Accurate fork is not espected with this instrument, but for Chapter IX Tho position of pronument points of the route may be fixed by intersections, taken from stations on tlic route, tlc position of which has been freed by traversing The forward bearings slould be talen to the furthest tisible parts of the route, 11 respective of distance. In settled weather an aneroid barometer may be used for finng levels (See Appendix II The clinometer on the back of the board is of use for measuring slopes roughly in the vicinity of the sketcher. 59. The principal use of a horseback sketch executed as above is to serve as a diagram to illustrate a road report The report being the essential part of the work, the sketcher must make notes as lie rides along, and must generally be on the alert. It is, therefore, not desirable to corint paces, for this system is vexatious and laborious and prevents the sketcher from studying the country through which he rides. For the above reasons the best way is to measure distance by time Allow 12 miles an hour for a canter, 8 trot, 4 under normal conditions. Then draw a scale of minutes at thic trot on the ruler. Thus... Scale of sketch 2 inches to 1 mile, - In one minuto at a trotzmile, or 235 yards, till have been covered This distance scale on the edge of will be represented by In using this scale at the walk, halve it. When walking half the time and trotting the other half, take three-quarters. * Practice in Leeping the horse at au cyen pace is essential. walk, ·55 If it is known that the particular horse which is being ridden has not got the normal speeds, a special scale sbould be made. The best pace to work at is a steady trot. 60. The cavalry sketching board is also very useful for work on foot, particularly when completing a previously prepared enlargement (see Chapter XII) It may also be used for making a road F-pl ........ 1--- 5 ! revolution, and to prepare a scale of cycle revolutions accordingly. CHAPTER XII ENLARGING SNALI. SCALc MAP AND ADDIXG EXTRA INFORMATION OX THE GROUND - RCPORTS. 61. The methods to be employed in enlarging an existing map to a larger scale have been described in Chapter VI, and cxcmplified in Figs 5 and 6. It may be expected in most future wars, that officers will be in the possession of small scale maps But it 13 not possible on a small scale map to indicate satisfactorily the positions of small bodies of troops It must also be reinembered that maps are rarely quite up-to-date, and that maps on small scales necessarily ornit details And certain tactically important information. It will thereforo sono times happed that a map on a larger scale is necesary, and this is obtained by enlarging the small scale map. It will now lo Salut, in urder to allow or greater space for the inclusion of act information, but care must be taken that nothing wrntial is omittcu.

·56 62. The best results are usually attained by the following procedure (a) Carefully study the tactical object insolseil srith the aid of the 2-inch map provided () Bicycle or ride rapidly over the ground, or to such high points as it is necessary to visit in order to appreciate with the aid of field glasses that special information is wanted. (c) Enlarge that portion of the incl map selected for the sketch to the required scale (d) Fill in the enlargement on the ground, cliefly by eye sketching, and make the necessary notes. (e) Finish off the sketch, and, of necessary, add a report. 63. With regard to (d), where the map contains a number of well-defined features, the position of which can be fixed upon the enlargement, the details of the country between such points can usually be sketchel in by ese without difficulty When, however, the map contains fes features, the position of wlch can be definitely fixed on the enlargement, it will usually he necessary to fix some uldstional ruling points either by triangulation or by hich can complete o fill in be able that he need not go over the same ground trice 64. The formation of the ground can be shown more completely than is possible on a small scale map by the interpolation of form lines, i c., approximate contours, between those obtained from the enlargement; slopes being shown as explained in Chapter V, eg, if the enlargement shows contours at a vertical interval of 100' interraediate 20' form lines can be put in by ese ורח 11 1 . not uniform the approximate place where the slope changes should be marked on the sketch, the steeper portion of the slopes being

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·58 ense, and it is desirable to keep thic mind alert to examine and treat het cac' 68. In drawing up his report the reconnoitring officer should bo as concise as possible, and should be careful to confine lurs informetion to what is relevant The most satisfactory method is to divide the report into two parts. The first part should contain a general description of the outstanding features of the reconnaissance, to evable the reader to get a grasp of the subject without having to wade through a mass of detail The sccond part should contain the details in tabular form For the same nature of reconnaissance (road report, river report, etc) the leadings in Part II, should tisually be ilie same; those in Part I, however, should be varied according to the tactical object of the reconnaissance The disadvantages of a cut-and-dried form are counterbalanced by the greater case with which items of ioformation can be turned up or reports collated Where the names of foreign plices or towns are spelt in various ways, the anglıcıscd form should be used, followed by the local form in brackets Care should be taken to distinguish between what are impressions or hearsay only and what are facts. 69. Road reconnaissance. i The information sliould supplement that given on the sketch, and not repeat what is already shorn ii The information sliould be definite, eg, it is not enough to know that animals can be tratered in a stream, but the numbers for twhich there is room, its depth, etc, must be giren. ui. Tactical Information - Definite information is specially impor- Thus it is pot suficient position Information of the position and force ont and lands, and of ·should be noted, with the direction and extent. The names of dirtual vii, Obserration Points - Places from which a view canal objects that can be identified should be mentioned, such as chamber, ix. Local Administration-System of local administration all be noted; the identits of influential individuals or functionaries of gmin kept in stock From the butclicts ascertain iſ the locallity In the forner seek for flour mills and find out the normal amount is kell-supportivo, or if mucb frozen mezit is brought in. For groceries tind out tlic biggest firing, and ascertain at what intervals of cus 59 suil for digging; loxalities wylich woull formu ar c'est part, artillery positions, on and enemy's, what the xpw #jibo, Jaros from which an extended very is obtainable and the shore Cellut fire; best lines of attack and counter-attack; 1991 setter water. In order to make a good tactical recomenar je wolle before starting, to find out with what a special i1ca" 0 sance is to be undertaken iv. Road Details --Roads should not be clasifiermilyly laxi, width, though information as to their width may be me para. 13). The surlace condition and material for youL. considered The ease witb which troops can play 1that is important. The nature of the fences or ditching this road should be mentioned. v. Gradients.-Only such gradients Blould be intima bir mill affect the rate of marclung vi. Bridges -- It is not necessary to Five details of sorry a dves, con nhould be fully repyntet om, in mechanical tratant, be noted. xil, Turnings ---Mention turnings only alien they ground wide hifficulty, e g., through a town where the names of clientemente country houses, &c. should be cstablished. 3. Supplies -For a thorough report on a district an (2]ate in alm. non tot) large number of farms. L th, height also word ·60 stocks are repetred the date of the last order will show how long present stocks will last. Find out how many rations of tea expressed in oz. and of sugar in 4 oz he has in hand, the lower number of the two divided by the nuinber of days the stock is estimated to last will give the approximate number of consumers Thus enables the number of grocery rations obtainable to be estimated, as other groceries are usually present in sufficient quantities. HILDINGS FOR PART II Distance in Miley. Place Details uf Hvad Remarks, Intermediate From 70. Rirer reconnaissance. 1 ir The leadings in Part I will vary according to the tactical object, those in Part II, which contains nothing but facts about the river, need not vary. ... ht 11 iv, Ice 3 inches thick will bear men in small detachments; 6 inches thick, horses and carts; 9-19 inches thick, wagons and gung.

·91
IIC nos ror Part II.
iser
Quase
Larpraches
Bonts
Details
Remarks
Suisson)
Right Left
1631h lank
and
Larges
usunity
Right Left
available
bank bank
71. Railray reconnaissance,
i It should be borne in mind that an espert rould be required
to write an adequate report on sbich to work a railcar.
ii. Stations - In ordinary circumstances a rough shetch of the
stations, on whicls the following information is shown, mould
suffice The approches, number of lines; cross-overs; number,
iength, lrcadili, nnd lcight of platforms; number and length of
fidlings; valer; turntables; end-lauling and other rampe; goals
sheils, lighting

·iii. Forming-up places -Places suitable for forming-up tronpa before entraining or after detraining, with their area, approac lies, water supply, &c, should be reported. v. Track -As regards the line itself, the gauge, any unusual gradients, type of fuel used, any triangles, and details of any bridges of importance should be notedIn case of a single line the distance between crossing-places. 73. Bulleting reconnaissance. ulation of taken as umber of Imber of veliicies per inhabitant should also be given n1 Billets without subsistence can be provided at varying rates The best class of village in a rich agricultural (listrict will take up to 10 men per inhabitant; a residential town or village with good houses and ride strects abont 5 men per inhabitant; while industrial towns with a dense population and a poor type of house will take still fewer. in There are various questions affecting bulleting, such as supplies, railways, &c: as a rule, these subjects should be treated generally in Part I. of the report, details only being given when particularly required. iv. Particular care should be paid to giving details concerning the water supply, any large buildings, such as schools or country houses, which will accominodate a considerable number of troops, and any open spaces where troops can collect or vehicles be parked. v. In many civilized countries chief officials of localities keep detailed lists showing billeting accoinmodation. Efforts should be made to obtain these. vi. In a billeting report based on the population of each parish, the small hamlets in each parish should he mentioned by name, as mell as the parochial headquarters

·63
Purt II.
ܨܕܕܠ ܐ
Billets
PO
of
Parish, Pop
Remarks.
Town,
Or
Village
Men.
74. Reconnaissance of an enemy's position toith a ricio to attack.
The following are the chief points on which information is
desirable
i. The general front of the pnsition, so far as it can be ascertained
The probability of advanced troops corering the real position till
have to be considered.
į. Points from which a good views of the country occupied by the
enemy can be obtained.
iii. Localities to rhicle the enemy is seen to be deroting attention,
and any otliers which would appear likely to be of special tactical
valac to him. The position of Ody trenchce, obstacles, &c., that
ran be located should be carefully noted.
ir. Lines which afford the attack most corer during their adrance
and which offer facilities for corering fire, both from gung and
rilles, wliere it is exposed to hostile rics and fire.

·Ut v Tactical points on the above lines of adiance and elsewhere, the possession of which will farour the development of superiority of fire over portions of the enemy's position vi. The manner in which the flasks are secured, whether ther rest on natural obstacles or whether there are any indications of supporting troops and works echelonned to the rear 75. Defensile reconnaissance. When it is intended to occupy a defensive position, with a view to subsequent offensive action, the chief points to be noted are -- i. The extent of the position, the localities of special tactical importance in it and the means of securing the flanks. in. The minimum force necessary to occupy tlc position ini The positions for the artillery and for the infantry firing lines These should be considered together, so that the best use of the ground may be made 1 The best line or lines for the counter attack. v. The most favourable lines for the enemy to attack on, and positions from which his artillery can best support such attacks. vi. Ang tactical localities, the possession of which might enable the enemy to develop superiority of fire against some part of the position. vii. Any advanced position, the occupation of which might have the effect of misleading the enemy and forcing him to a premature deployment. 76. Notes on the way to finish up sketches will be found in Appendix III CHAPTER XIII. EYE AND MESTORY SKETCHING 77. X{though it is improbable that an officer unprovided with an officer in rommand of an outpost company, he would probably ·65 have to furnish to his superior officer a sketch of the ground on which his troops were disposed Joreover, a plan-sketch is a useful addition to any written report Without any instrument whatever, it is possible to execute, with fair accuracy, a plan-sketch which from a military point of view may prove of considerable value The making of such a sketch is much facilitated by the mastering of the principles of sketching described in Chapter X Tho sketcher requires a pocket book, such as Army Book 153, or a flat board, and ruler Board. A piece of board of convement size, a smooth-covered book, the lid or a biscuit tin, or any simular article to which a sheet of paper can be attached (To keep the paper stretched over the board, or other article, perhaps the simplest way is to secure it with two pieces of string, tied tightly round paper and board at either end) Ruler. -A slip of wood, or stout cardboard, with a straight edge. Not being provided with a protractor or a scaled ruler, the sketcher must construct a scalo to which to draw his sketch scale to be adopted for any sketch depends on the area of the country to be sketclied, and on the size of the sheet of paper available The the sc pocket being most officers' pocket books squares of a certain size aro ruled on the pages; eg, in Army Books 159 and 153, the squares are much. Ir, therefore, a book of thus kind is available, a ready-made scale is at land, otherwise a scale must be thougiit out. Thic shetcher sliould sot net at scalo should be drawn at ti hatin If at como future tinie a fo hind, disidel accurately ir yards to the inch can be forlat out. 2 21475 ·66 It is useful to remember that the lines on a sheet of ruled foolsapare as nearly as possiblo one-third of an inch apart. So a strip of such paper, cut lengthwars, makes a handy scale, the intervals Letneen the lines bemg approrimately equal to 100 yards on the 6-inch scale, 150 yards on the 4-inch, 200 on the 3-inch, 300 on the 2-inch, and 600 on the l-inch Another useful measurement to know is that the diameter of a halfpenny equals one inch 78. The sketch is executed by first arbitrarily fixing on the per point to represent the position of the shetcher. Then, pivoting his ruler on the point thus fixed on the sketch, he aligns the ruler on dıstant points, and drars mys on his sketch in their direction. It is necessary for the sketcher to get his eye well down along the alignment of tbe ruler so that the direction of the ray may be obtained as accurately as possible The detail required on the shetch is filled in before the sketcher moves from his position. Having completed thre, he marches in the direction of a point whose direction is fixed by a ray on the in around his new station. 79. It will often happen on service that reconnaissances have to be made under conditions which make any sketching on the ground impossible In such circumstances a memory sketch will often furnich - neofol amnlament in Then noccible wowok tornet In observing ground with a view to making a sketch of at .subsequently from memory, 1t 18 important to distinguish between the essentials for the purpose of the reconnaissance and details of minor importance. No attempt should be made to burden the memory with the latter.

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·PLAN 10
To fuce wine 67
-
PLANE-TABLE, TORTABIE, MARK II, 18 INCHES SQUARE
20175

·67 PART II. CHAPTER XIV. PLANE-TABLE SKETCEING. The plane table. Nore.-The use of the plane-table at the military colleges 18 authorized for the purpose of teaching cadets the elementary principles of the construction of a shetch 80. The plane-table is merely a portable table. The tatile or board can be carried separately from the stand, and when fixed to it can be turned round to set" the sketch without moving the legs. The stand is usually a folding tripod, and, for greater compactness, is sometimes collapsible The adjuncts to the planetable are the sight-rule and the trough compass, the plane-table should also be provided with a waterproof cover. 81. The sight-rule should be about as long as the shortest side of the table, and the fittings should be of şunmetal or brass, not iron or steel A common de ... rear rane is too small. of the tops of the vanca the vanes are upright, to enable rays to be taken on steep slopes. It is convenient for the sight-rule to be graduated with useful scales, for instanco, 2 inches to I wile, as in the Service pattern An Ihntonchnamnnnn ghould animate-1--La... 11 prismatic compass can be used instead. 83. Mounting, plane-table-With an ordivary, plane-tablo which lias a plain board, pin tho paper on to the board with dramingpins. All arrangements of clips should be aroided.

·68 84. The plane table is the most accurate instrument employed in making miltary maps and sketches and it is important that the student should master the methods described The following are general maxims which slıould always be observed – i See that the leg-screws and clamping-screws aro taut before beginning work ii Spread the legs of the table widely, especially with collapsible patterns (since the steadiness of the table largely depends on the spread of the legs) In soft soil the legs should be irell pressed into the ground. The board should be horizontal in Alyaya keep the pencil sharp, there should be no error in dots surrounded by a circle. is When it is required to draw a ray from a point, put the pencil upright on the table with the edge of the base just touching the point, and lay the sight-vane against the pencil, Instead of a pencil, some expert plane-tablers use the finger ; but pins would not be used by a good plape-tabler v. When drawing a ray from a point on the sketch, set the point of the pencil into the point first, so as to get the correct angle at which the pencil should be held when drawing it along the sight- Without this precaution large errors creep in v. Whenever the plane-table has to be set up or oriented by a vano which to lay the sigbt-vane vii When drawing a my to a distant object, mark its approximate position, as estimated, by a small circle on the ray. Write the name of the object along the ray. viil. In making an intersection with a second or third ray, it is not necessary to draw the whole ray. About a finch of it across the point of intersection will suffice ix Never set the plane-table by the compass if you can set it by ad alignment on some distant point or points already fised ·69 85. The steps to be taken in making a plane table sketch are as folloss :- i Select a Base Line. This should be on level ground It should occupy a fairly central position, though this is of no great importance Both ends of the base should be visible from well-marked natural points in the area to be surveyed, and from each other. The length of the base would usually be from mile to 1 mile, but the longer the better. A good rule is that the base should be about 2 inches long on the paper, but this 19 longer than can usually be obtained. If possible mark the ends of the base; or, if this cannot be done, measure between existing points or objects; or else measure in the same line as two existing objects A base is usually selected on high ground because its ends then aſford goorl points of observation In some districts, Lowever, wbere the higher ground is much wooded, and gaps are short, it is often better to select a base in an open valley. From this the prominent features of tbe hills on each side can be more easily fixed, and, when fiscd, can be used as stations to fix detail in tbe valley. ü Measure the Base. This must be done by careful pacing, the accuracy of the triangulation depending on the correctness of the base. 11. Fix Points by Intersection. The most suitable position for the base on the board must be carefully considered before commencing work; the amount of country to be surreyed, and tho posítion of the prominent points required for resection, being taken into consideration, Set up the plane-table at one end of the base, and draw rays to the other end of the base and to prominent obtects within the are to be surveyed, or not far outside. Place the compass in its borc the compass until the needle poir tuen amir a line on tio talle at north end Remove the compass subscquently in the course of the trork at intersected stations. Go to the oulier end of this lase: place the sight-rane Blogs the pencil line representing the base ; set the plane-talle by moring the board until the sight-yone is aligned on the first end of the base; then dmv rays to the aime prominent objects used before, thus fizing their prition by intersection. 11 10 ·70 It may sometiires happen that one end, A, of a base AB, has to be selected because there is a prominent object there, but that a Letter station, C, is close at hand to take rays from. Chas, however, no object to define it, eg, it may be in an open field It imy be used to observe from by fixing its position from A. The board 18 set at A on B, a ray is drawn to a big stone or stick put at C, and the distance is measured carefully and plotted. The object at A can be used for resection purposes. Next go to one of the points intersected which makes a wellconditioned triangle with the base, test its position by setting up by one end of the base and by an alignment on the other, and then draw rays to all the other intersected punts which are visible and to any new points which may be likely to be useful Except in the immediate neighbourhood of the base, it is desirable that each intersected point should be fixed by three rays, particular care being taken to ensure the greatest possible accuracy in fixing points which may afterwards Le used for resection It is by no means necessary to cover the whole of the sketch with intersected points, but it is important that the positions and levels of ruling-points should be fixed, others being sketched in by eye to save time It often happens that on proceeding to an intersected point, X (eg, church spne) the table cannot be set up over it, or the ground just there may afford no view of points you want to fix, The table should then be set up near it, and on a line between it and some other fixed point Pace along this line the sbort distance you are from X. plot it to mark the point over which your table now is, and work from it as a station iv Fill in the Detail; mainiy by Resection.-Resection from three known points, sounds a fornudable process, but in reality it is very simple *It is the principal means by which the bulk of the detail, which cannot be eye-sketched from intersected rulingpoints, should be fixed The method is as follows -- Set up the plane-table at any point froin thich three previously fixed points can be seen. Orient the table by the trouglicompass, and from the three fised points draw back-rays If these three rays pass through a point this point is the required position.

·71 If they do not pass through a point, the rays will form a small triangle called the "triangle of error." The true position is now to be determined by the following rules I. IE II. In the latter case the position will be such that it is either to the left of all the rays wlien facing the fixed points, or to the right of them all Of the six sectors formed by the rays, there are only two in which this condition can be fulfilled. III. Finally the exact position is determined by the condition that its distances from the rays must be proportional to the length of the rars, ie, the position on the sketch must Le nearest to that side of the triangle formed by the shortest ray, and furthest from that formed by the longest ray. Firo. 13 3 In Fig. 19, for instance By condition l die point must be outside the trianglo of crror. in sector 6 in sector 3 ·72 - MU By condition III the point must be in sector 6, since the distances from it to the mys must be proportional to the lengths of the rars, and by estimation it will be where alotn. Haring thus determined the position, place the sight-rule along tho line joiaing it and the most distant of the points used; set the sight-rule on the point by revolving the plane-table; clamp,and test on the other two puints If there is still should, however, ha el The best positi points, of which 19 Usunt Accuracy of potannia pear, accuracy of getting is Generally fix from near tuwe fixings by this method VOLA Tupuy and accurately. It is the essential foundation of all rapid plane-table sketching The plane tabler in open country peed not pace or measure a yard after he has fixed his base In addition to the speed which results from a free use of resection there is also a gain in accuracy, since there is no piling up of errors, and each fixing is dependent only on the main intersected or other trell-fixed points. When there are a number of points, ang three of which may be used for resection purposes, recollect in choosing the point to be used that- (1) When the three points chosen, and the observer's position lies on or near the circumference of a circle, the accurate determination of the observer's position is not possible by this method (2) The three points chosen should be such that the rays from them do not intersect at acute angles, and thereby make a badly shaped triangle of error. Choose points which are most accurately fised on the sketch (eg., those of the base or directly fitorl fail Berinnan ber TL 4.U HUL Luemselveg bet. uuvutilely tixed on the sketch The method, horrever, • To make thus clear, take a polnt anyti bere in sector 3. It will be seen that it lies neater to at least one of the long raya thaa to the shortest ray, and condition III would not be fulálled. f ·73 • the is an absolutely exact and accurate one. It will have been does that this sbould be remembered. Two useful metbods, which can often be adopted with good results, should be noted (1) If the sketcher can place himself anywhere on a line prolonged through two points previously fixed, he can set his board by them and fix his position on this line by resecting from any thnd fixed point which gives a good angle of intersection (2) If on setting up at any point Cit is noticed that a ray to some other useful point D bas been omitted when at a TT intersection of these rays is the position of D. v Resection from Two Points.--It will sometimes lappen that only two fixed points or stations are visible; in this case the planc-table must be oriented by the compass, and rays must be drawn back from the two fixed stations intersecting in a point which must be taken as the required position. It is clear that such a fixing (lepends entirely on the compass, and may, therefore, bo very inaccurate. In parts of South Africa such a fixing would, on account of local magnetic attraction, be entirely wortbless, and it is obvious tbat as a general rule compass fixings drawn in; a combination of measurement and estimation should be used; the aniount of estimation permissible will depend on the scale. Thus, on scales of 2 inches to 1 mile and smaller scales it 11 Whca time presses, minuto accuracy must be sacribced.

·7 Traverse Detail which cannot be fixed by Resection, It will sometimes happen even in open country ihat there are parts of the work, sueli as vallers and woods, in wbich planetable fixings cannot be made, in ilus case it is necessary to have recourse to plane-table traversing Pline-table traiersing bas to be much used in flat country unprouded with prominent landmarks, and tras used in the mapping carried out during the operations in Chin2 in 190) The method 18 as follows - Set up the plane-table at some knowo point and orient it by some other known point that can be seen, the further away the better Then procced as directed in Chapter X, fixing the direction with the sight rule, and pacing the distince Traversing does not give accurate results, and should only be used where uzaloidable qc Thanya tin nathade of rein the nlananble to fir the s sketched in lere sufficient Experience will teach the sketcher How to select tue uruer ixt Ica he tvill visit ruling points, so as to end at one which affords a good view for sketchung in hy eye the remainder of eich section Beginners usually make the error of utilizing instruments too much in field sketching, and of fixing far more points of detail than 19 compatible with rapidity of work It is, therefore, important to remember that when ruling points are fised correctly, small disred sath nation is student CHAPTER XV. Paxon MA DRAWING. 87. A useful branch of field sketching is the representation of a landscape in a conventional form, or the art of representing the country in elevation instead of in plan. Such sletches, which are ·75 called pinoramas, are useful to illustrate a report, and may add. consulerably to its value and clearness A panorama 13 often an invaluable adjunct to a report upon an artillery position, and may be of assistance when lung at mowing objects from under corer, for switches, and in night firing (see Field Artillery Training). It may be premised that, from a military point of view, it is not necessary to be an artist to produce a useful panorama, Indeed, it is better almost that the artistic sense should be absent, and that ld be looked at with a cold, sketcher would note rather ry purposes than it beauties of colouring or the artistic effects of light and shade. The beginner often feels much discouraged because his first atteinpts are so unlıke what he wishes to draw, but with patience and practice and a close attention to the hints in this chapter, he will find that in time he will be able to produce useful nork Let it be understood that lowever rough the picture may be, it will still be useful if intelligently drawn. Another difficulty is that of crawing the trees, houses, c, as they are seen in the landscape. Absolute accuracy in the details of their appearance is not essential So long as the sketcher can faithfully produce the outline of the important military points of the panoranı, the other details can be drawn in a conventional manner It is better to stick to bare dept such as is Unnecessary macts from its clearness Let the beginner learn by degrees, drawing small and easy subjects to coinmence with, before trying anything too ambitious Let'lum copy other dmwings, and thus gun conGdence in his own powers Plate 17 shows some examples of methods of drawing objects in nature in a conventional manner. 88. Tlie sketcher should study the ground very carefully before cominencing to draw it. Ile should make a free use of ihe field fligyes or telescope to assist in resolving details which appear cep usel and in defining accidents of ground that noe not clear to the naked cc. The more carefully the country is studied beinreland. Ilie casier will it be to draw it. In commenting to mama paniram the first tlung in do 18 to cline a suitable point of view from white to sketch it Tuis depends on two things : 90) The a I 1 ·76 country to be included in the panorama, and (b) a position from which a good view can be obtained. In a measure, these two conditions are closely associated. The trider the extent of the panorama, the further off must be the position from which it is drawn. It will be understood that the wider the visual angle, the more inconvenient it is to draw all that it includley, and it may thus be necessary to make a panorama of the cquntry in tro or more sections and to join them togetlier afterwards Having chosen the point of view, the next task is to draw the picture Here the beginner 13 confronted with a series of difficulties, boine of which are | How to begin. 11 How to keep the dimensions in the picture proportionate to the apparent dimensions in nature in To overcome the difficulties of perspective, and to get the receding effect of distant objects. iv What to include in the drawing and what to leave out. To take these points in detail- · Ferst select the position from which the sketch is to be made. This should be some point where the sketcher can sit down comfortably with a good view of the ground on which he wishes to report The position should be as central as 13 convenient The beginner should use squared paper, such as that in Army Book 153 Until he has acquired some skill in the use of a pencil he should use two, one bard for drawing in the distance, the other medium for the middle distance and foreground A ruler about a foot long with a piece of string about one foot long tied round its centre, will be of assistance in measuring distances and angles. 1. The next step is to settle the length of the panorama This depends on the extent of ground to be reported on, but if this 18 large it is not necessary or advisable to attempt to include tbe whole in one panorama As much as is convenient may be drawn from one point of view, and the remainder of the ground be shown in a second panorama, viewed from elsewhere, normally about one foot, ie, about the length of a double sheet of Army Book 153 when opened at the centre, may be taken as a convenient Limit Hold the ruler horizontally at such a distance from the eye that one end coincides with the left of the distance or skyline of the ·77 country to be sketched, and the position of the thumb on tho ruler with the riglt Nov, without altering tho position of the rulur, 19 18 lopoi laut as uluer wise lue reduILS WIl vary. Mark off on the paper the horizontal limits thus incanured on the ruler, and then measure the vertical lunits in a similir tir loy holding the ruler vertically Thebo vertical limith would do when on both ends of the paper Now consider the skyline carefully and eclect amos pronutrit point on it as nenrly as possible directly opgamite to your pour The hill with the flagstaff on it in Pluto 18 in such profit. IIx the position of this point by mensuring its (stanco froin the culpa of the paper and its height from the bottom of the papor. I this point mcagure off the distances to other prominent point, AICI as the two fir woods on the skyline (l'late 18), measure antitally their relative heights, with reference to the bottom of the open and mark their positions on the sketch. Next consider the middle distance and the ground many yw, Select, if possible, some tall objects wluch cut the growth I sketched vertically, such as the two railway signal, la house and the outer trees of tho fir wood in the lele Sopww. Measure the distances with the ruler as before, and tunk lewa tions of these objects on the paper with horizontal lines, suitable tall objects are available any prominent object will ! In the way the positions of a number of ruling minimam froid, and a framework is made in much the same way as whru mabing triangulation ++ 1 441 442 VIL'UE Lung quan uwuwy dystrophesy purposes. First of all, as regards the size of the objects. It will be ostren in looking at the landscape that, as objects are placed fugiem, they apper enialler. Therelore, make them so in dramoyon panorama.

·78 The further off the details in the country are, the thinner must be the lines with which they are drawn Thus- In drawing the nearest part of the picture, use a medium pencil with thick strokes FIG 20 1888 A simple Example of Perspective ( The vanishing point A to be specially notea) The middle distance, which lies between the foreground and the background, should be depicted in strokes of medium thickness, or with an ordinary pressure Lastly, the background, or far distance, should be drawn in fine strokes with a bard pencil, or with one used with a very light band. In other words, the nearer an object is, the thicker and heavier the strokes with which it is drawn, and the further off it is situated, the thinner and bgbter must be the strokes.

·11-3 building, the background, and work, gradually thickening the strokes, 79 iv. What to include and what to lease out of a panora'na 18 a matter of judgment, but the following points are of importance Al details that have any bearing on the military situation should be carefully drain. For example, in making a panorama of an pemp's position, hedges, fences, &c, that you he held by bun, or that would assist an attack, should be put in carefully Obstacles such as riters, marshes, and so on, are of importance. Church torters and steeples, factory clumneis, outstanılıng and easily recognized trees, such as poplais being landmarks are useful. the ground importance, not all the e11 When posius villages it is not necessary to put in every house, hut to represent genemtly the shape and extent of the village, while carefully drawing the outline of any special feature that Berres as a landmark, such as the church or a big house or There is always a tendency to exaggerate the beights of hills, this must be avoided, as it leads to misrepresentation alo a tendency to exaggerate the size o bouses, &c, la the distance. Tis has the result of making these appear nearer than 89. Flaving considered the above difficulties, the sketch can now le commenced First draw in the outline of the skylne ligbtly with the aid of the points alrevly axed. Then draw in as accuratels os poesible the other principal objects, the position of shich has liese objects In finishing the picture, each of tliese sections shouki be taken in detail and all that there is to be seen in it of military value should be drawn in, and thus the picture is completed, section The preliminary work of & Jandscape sketch should be drama with a very light hand, and the smoother the paper the better. la finishing the drawing, it is best to coramence with It is of great assistance to learness to share water, toads, &c., in charentional colours by means of chalks, they are by section ·80 The last thing to do is to insert the information, viz, the point, referring to a map if there is one, from which the Betch 19 drawn, and the direction in which the centre of the picture is situated, the names of places and tlie ranges to them, &c The date and state of the weather should be included, a panoramic sketch is much affected by atmospheric conditions For these and other details, see Plite 18 Plate 19 shows a sketch prepared on squared paper for use in an artillery position, Plate 19. being the corresponding range-taker's card Plate 20) sbows a sketch actually executed during the Chitral Expedition, 1895 Thts, altlıough a very useful sketch, omits some points which it frould have been desirable to insert, eg. tlio compase direction Plate 21 shows a sketch executed by one of the British officers attached to the Japanese Army in Manchuria to illustrate luis report on the Battle of Liao Yang The sketches represented in these Plates show in some cases more shading, dc, than is either generally necessary or possible under service conditions, the process of printing having considerably elaborated the originals 90. Finally, the telescopic sketch, as it might be called, may be considered This is a sketch which is made by the help of a telescope or good field glasses, of a distant piece of country, of wluch tho details cannot be clearly seen by the naked eye At first this tray seem difficult, but practice will soon overcome it First the subject should be looked at carefully with the naked eye, and an outline enlargement of it should be made on the paper, Then telescope the sketcher can look at once on the paper and draw in what he sees ·81 CHAPTER XVI. ELENENTARY INSTRUCTION IN MARCHING BY THE STARS. 91, Night marching under the best conditions is an operation demanding the greatest care and practice on the part of the guide The method of night marching by means of the Service Prismatic Compass has been described in Chapter VII The most favourable conditions for a night march are a clear starlight night and no moon. The guide first ascertains the magnetic bearing on which he intends to march during the night He next selects a star, which has the required bearing. The methods that can be employed in the selection of the star are as follows: Thc black direction mark on the glass face of the service compass is turned till it coincides with the required bearing shown on the external ring. When the black arrow lead is made to correspond with black direction mark, the line between the luminous patches on the lid indicates the line of advance. 1 take a fresh observation. 92. The most convenient stars to select for marching on are those which happen at the time to have an altitude of from 15° to 30°; stars below 15° may become lost in haze, whilst for those above 300 the lead has to be inconveniently raised Speaking bmadly, a star at thcsc altitudes till rarely move more than 5° in azimuth (ie, to a fank) in 20 minutes. Llence if at the end of every 15 or 20 minutes the observer halts and takes a fresli bearing, he can count on kecping direction correctly. Although it is of assistance to an observer to know the starr, it is not necessary tlint he should do so. Anyone cad, trith care, march on a comisa baring, with the stars as points to direct him, with satisfactory results, although he may be totally ignorant of the F ·82 names of the stars or cren of the constellations. The great point is to be suro that the compass bearing is correctly taken and prolonged, and that the star selected is adhered to until a change is required. APPEYDIX I FOREIGN DIEASURES Actric System- Used in ܂ ܐܝܬ.ܝܙ . ܘܢܚܝܘܢ ܀ DA...T land, Turkey, United States (partially), Venezuela MEASURES OF LENGTH Incbes. Yards 31 limetre Centimetre Decimetre Metre Kilometro 033 394 3.937 39.37 39370 79 001 011 109 1 091 1093 633 SQUARE BEASURES Sq. yards Acres. Centare (square metre) Are (100 square metres) Hectare 1 196 119 603 11900 333 025 2 471 ·83 OTHER FOREIGN BEASURES. . Russia Denmark Persia Egypt China Sajen Verst (500 Sajen) Sq Verst Desyatına Mul (2,400 Rode) Farsakh Zar (16 Gercho) Kadam Diraa or Pik Kascaba Feddan Ts'an Ch'ib (10 Ts'un) Chang (10 Chib) Li (Ri (36 Cho). Cho (60 Len). Ken (6 Shaku) Shaku Square r: cho Tsubo Ungal Hath Gaz Kus Bigah Same measures osed 19 in England. = 7 feet. = 1.166 6 yds. 44 of a Bal, mile. = 2.7 acres. = 4 68 miles = 3 87 miles (about). = 40 96 in. = 1 foot. = 22 83 12 = 11 6 feet, 31 04 acres * 1.41 in. = 14.1 in = 141 in. = mile (about). = 2 40 miles = 119 3 yds 1 988 yds. = 11 93 ang = 5.953 99 miles = 2 45 acres = 3 95&q yde = 75 in, # 18 in. = lyd. = 2.000 ydy. = 1,600 sq.yds. Japan Indin Unitel States ATTENDIX I. THIE ANEROID BAROMETER. Aneroid Barometers.-For military trork a 24-inch barometer reading to 0.0*0 feet is a useful pattern. In settled weather the aneroid barometer is often useful in thetching, especially on' snall scales where the contour interrals F?

·are large. For instance, in sketching on a scale of 1 inch to 1 mile, where the intervals will be 50 feet, or on the inch scale with intervals of 100 feet, the aneroid will be found most useful. The aneroid should not be used in unsettled weather when the atmospheric pressure is varying An aneroid used for field sketching should be provided with a movnble scale of heights in feet It starting from a point of which the height is known, the scale should be set to that height before beginning work, or else a plausible height should be assumed the reading should also be taken on returning If there is a difference, the intermediate altitudes should be corrected in proportion to the time which has elapsed. An aperoid should always he read in the same position, either always held vertically on a level with the eye, or always horizontally, the latter is better Severe tapping is not good for an aneroid barometer In changeable weather barometers arc, of course, quite unreliable. Diurnal variation of the barometer. This variation, which is t'ime of year On account to arrange for checks on ible, however, in field : APPENDIX III. FINISHING UP SKETCHES FOR TACTICAL SCHEITES. 1. Sketches should be finished up with clearness and decision "Can I read this in a poor light?” "Can the eye rapidly pick up any special information likely to \be wanted ?" "Is information given so definitely that a draughtsman could trace it without hesitation as to what is intended ?"-are types of useful reflection ·85 2. Written information takes the form of: (a) Reports. (6) Marginal notes Instructions for writing reports liave been given in Chapter XII. Short statements about particular features of the ground are better given in margins with a reference number, thus -(3) on the feature in question and in the margin opposite it. They must not obscure the sketch 3 In making a statement, distinguish between facts known to yourself and alleged facts based on information received, eg, a marginal note about a river “Fordable for infantry at (7)," would bo wiong if not ascertained personally, and should be " Farmer Schmidt of (4) states fordable at (7)". 4. It 18 important that points on the sketch, such as cross roads and underfeatures, farms, &c, of tactical importance, should have a designation on the sketch. It may be necessary to refer to them in reports, orders, &c If such haie no ascertainable name, or if there is doubt about it, a good expedient is to supply them with a letter, thus -(1). af 1- 01 tuolul Barns 2 miles apart on the Orduance Survey 1-inch map of Wortling The licading, printing, notes, and heights should be en Lored so that they can be read easily when the sketch is held 60 that the ground can be examined when looking towards the enemy. Enlargements will usually be made with the N. at the top, and the direction of printing, dc., may have to be adjusted to the net direction required 7. All shetches should contain (a) A scale about 6 inclus long A statement as to the V.I. used. (A North Point lettered "Magnetic." If the variation of the compuss is LOWA, plot the true Worth Point also.

·UU
(c) Clear signature of sketcher, with date.
(d) State of the weather.
(e) Tiending stating the general purpose of the sketch. To
obviate wrongful deductions being made by anyone using
a copy for another purpose.
APPENDIX IV.
MUTUAL VISIBILITY OF POINTS
Two quick methods of determining whether any point Bis visible
from any other point A are given below –
1
1.
1
An
Sulipose there be
auppose the height
off on the plan the
kuppose AD = 1,200
Slope AD = a drop of 40 feet in 1,200 yards
40
1
1,200 X 3 90
Slope AB = a drop of 100 feet in 2,700 yards
100
2,700 X 3 gi
That is, the slope AB is steeper than AD; therefore, the point D
will obstruct the line of sight AB.
1

·87 Suppose D has been found to be below the line of sight AB, lut but there were several others points E, F, &c, which might obstruct FIG. 21 +JOO A 1700 far D280 8.200 1200yas 2700yds he line of sight, each could be tested in turn. In this case it might De quicker to proceed by the second method. This latter is best shown by an example.- Fig. 22 140 100 200 200 ras 120 240 200 240 220 180 100 100 200 fono (sor ! وه c 140 Tlo aboro plan represents a portion of a map contoured at 20' vertical interval. The line AB represents the line of sight: divide AB into a number of equal parts corresponding to the number of Lil) Itaով Similitis ate. But at c, where tho 210 feet contour cmses the line of sight the height of the latter is 237 feet (about), hence the ground is

·higher than the line of sight at and close to this point. Now, as
this line of sight is an even slope from A to B, therefore the
visible.
is unnecessary
11
2
FIG, 23.
300
A 300
280
200
240
220
200
1ao
8180
In the example given, A and B have each been assumed to be on
apland wohlv
Ll.
according to the V.I of the map contours), and then to compare
the heights of the various points on the line of sight with those on
the ground.

·89 APPENDIX V NOTES ON THE MAPS ISSUED BY THE GEOGRAPHICAL SECTION OF THE GENERAL STAFF FOR THE USE OF THE BRITISH EXPEDITIONARY FORCE ON THE CONTINENT. The principal maps issued to the Expeditionary Force on the Continent are as follows:- (1) Large scale or tactical maps France auto, or about 14 miles to 1 inch. Belgium Tookoo, 1.58 miles to 1 inch. Germany. - Tootoo, or 1-58 miles to 1 inch. (2) A map on the zootor scale or 4 miles to 1 inch of all three countries In addition to these maps there is a general map, commonly known as the strategical map, of Belgium and north-east France, but this is only issued to the Staffs of Corps and Divisions. Maps on large scales are also issued, as required, of special areas A description will now be given of the principal maps (3) crédo map of France (Plate 11). This map bas been reproduced from the original French map. The original is in black only, but on certain sheets (number to 24 on the Indes, Plite 25) contours At 20 metres interval have been added. These contours must only be considered as approximately correct. The shape of the ground is, however, well shown by hachures, wlich vary in strength according to the height and steepness of the ground. It is important to appreciate the significance of the hachures. The clearness of the map has necessarily suffered in the photo graphic reproduction of the original engraved map, and the general appearance of a sheet will sometimes appear confused When a map is actualls in use. however, the general appearance is not the important point. The few square miles of country which are actually ·90 being traversed, or on which the operations affecting the individual using tlie map are being carried on, are all that matter. A careful examination of the map will usually reveal the nature of that country, and in all cases it is fully worth while to make such an examination, The conventional signs and translations of the French terms used on the map are given in the reference at the foot of each map. They should be carefully studied This inap is not divided into squares with reference Lumbers and letters in the margin (+) Todo oo map of Belgium This map bas been prepared by the Geographical Section of the General Staff. Details and names le black, water blue, contours brown, woods green, and the main loads are coloured red The shape of the ground us well shown by the contours, which aie at 10 metre intervals, or about 33 feet Numerous heights are also given in red, and it is important to remember that these heights are also in metres The class of the roads is indicated by colour, and in most cases the information given is reliable The condition of roads, however, varies from time to time The state of the road depends on the weather, and the classification of the roads must not be taken for more than it is worth. It represents the best information available at the time the map was prepared One special feature of this map is that it gives the populations of towus and villages, according to the latest information at the time the map was being drawn, which may be anything from 5 to 8 years ago Here, agan, careful study of the reference on each map is well worth while. The map has reference numbers and letters in the margin, which refer to the sections into which the map is divided by the lines of latitude and longitude drawn across it. (5) The idono map, of North-west Europe, including Belgium and parts of France, Holland, and Germany, is in the same gencial style as the too's op map of Belgum, but the symbols used for railtrays are different. The map requires but little explanation Contours are at 50 metre, or about 161 feet interval, and heights are also given in metres The rivers and their panies are boldly depicted, which makes it easy to read the map quickly. inn flat that the contours are not the shape of the tween two rivers, d224 ULLE Were wu te vul une ut Lw uliu chere are none the ·91 country is practically fat, and where there is even one the con lieight or value will indicate the extent of the rise Most of the area covered by these four sheets is very thu inhabited Numerous scattered bouses will be observed ) moore Lave of course been omitted, but the endeavour bas througliout to indicate the general character of the country. The Ardennes begin in the East of Sheet 4, and cont throughout Sheet 5, and these areas have a different characte the rest of the map. They are thickly covered with forest, and contours are here close enough together to show the shape of ground The map is divided into 2-inch squales, which can be refe to by the letters and numbers in the margin Tbe length of sides of the square is 2 inches, or almost exactly 8 miles (6) poor map of France Maps of other areas have Lurriedly prepared by copying the French map on the goosoo pod reducing it to the protoo scale A large area of France been prepared in this style and also two sbects to the East ol area covered by the N W Europe series. These maps require little explanation, but it should be observed that the contour at 40-metre intervals as on the map from which they were co It wa to pr any The sheets of N.W. Europe and of the French series, r on the s. ex that thic Curope and sheet: to the East A new sheet to be called 24 is in prepara and lies immediately North of sheet 6. (7) Maps of Germany are, or will be available on the to and mohoo scales. A specimen of the German Thakor is in Plate 10. The toboo will resemble the sheets of N.W. Eu cxcept that the contours ill be at 40-metre intervals. (8) The Strategical map of Belgium and N.E France is pret on tho larer system, the shape of the ground being indicate tints which vary in depth according to the height. It i A scale of notio, or 6 miles to one inch, and is a very general map. ..

·96 PAGE Example of perspective 78 Examples of method of cop. structiog a scale without the protractor 14, et meg of slopes 21 Esercises for studying contoars 25 peace 57 Eje use of for fixing deta) 11 PAGE Grarents, reference to, in road reconnaissance report 59 Ground, comparison of large and small scale maps with the 47 formation of, metbod of showing on an eolargement of a small 56 map reading on the 45 necessity for visiting not obviated by mp3 study of the prior to commencing a ranorama drawing 'sketching scale mnap 11 99 11 F. 11 H. 18 18 1) 19 20 Heath and heather, how shown Herghts, how show Hili features, metbods of representing met bod of sbowing in field sketching Horse, paces of the Horseback sketcb, use of 10 19 11 22 54 54 Facts, importance of stating in a reconnaissance report .. 58 to be stated in notes on maps and not orders 57 Features, bill, method of repre. senting 20, 28 Field sketch, definition of 7 features to be shown on a 7 sketches, approved con ventional signs for 17 size of scale for 12 use of 7 sketching, method of show. ing hull features in 22 Fonibipg sketches, notes on 81 Foot, use of cavalry sketching board for work on 55 Foreigo measures 83 Form lines, how shows 18 Dumbering of 57 22 Forward bearings, bow taken French map (speciznen) 42 11 I. 60 12 17 use of 55 Ice thickoess of which will sunport troops, &c. Inch to find tbe number of miles to a Information, adding extra to en. largement of small scale maps, 17- portance of as to enemy'e troopy and works to he shown on a sketch form of written military, lack of in maps Om18810n of, from an enlargement of a small scale map preparation of 67 85 G. 41 General principles of sketching 47, ct 84, Gernuan man (specimen) 42 Glasses, field, use of 75 57 12 ·07 13 PAGE Levels, spot 12 use of anerou! 12pmeter for Axing Line, base, selection of the (planetable sketch) 69 Larcal admiarstration, reference to rund reports Luminous paint, use of for prepara comp98% tor marehssig . night vt WY PACE Information regarding rivets to be shown. 18 regarding woods to be supplext 18 imyoused in a recon nasssance of a enemy's p0927023 with View to attack required in a rosu 1 ECO521310 Oce tactical, required at a road TCCODxnce 10 bo jaclude 33 rewst of bullet ing reconnaissance G2 to be located in report of a rail. way reconnais972CP 61 topograpliscal, adu. ing to a man type of to be 13- cluded in A FOCUS Daissance report 58 Instrument, Cr use of by begingers sketching N Khetching without Intersection, we of, for fixing posts (plantable sketcb) M. 33 30 . 37 8 ti 29 se 42 63 . Jagnetic bearing, methot of Axding the bearings north, Erow glown on seryxe pristalic COKLKES Tariation), 6s dag the Manuel, diyssich of th4 lap, deling topographicalto x enlarging French (specimen German information omitted whes enlarging ► making principles under meibolsot setting litary, points to be shown on a reading, oa tbe ground girocedure for 823) Balc, elbont of slowseg grouod formation on au calaremento readas. ftann for fictedry la to find ode's position on : » When to Hips in the to the sody o! grouo uod tasub stitute for aprirs, kerals of Iring 17 K. Koolis, Axing the fact 10% of on an enlargement of a sinal . sale mar 61 19 $$ * layer item, mapa on the lettet, men of metric um Interior essential tops for FY+ ·98 . 17 tion in .. P101 filitary sketch, essentials of. linutes, scale of .. 51 Models, use of for allestrating contours 20 Mouated, rules for sketching 53 Watual nubility of poinës 86 et seg + N. 11 49 97 19 .. 11 3 . 10 PAGE Maps, detul omitted from smail scale maps 46 lack of military informa. 41 large and small scale, comparison of with the ground ... large scale, use of 7 limitations of +1 methods of enlarging 26 military, classification of military, use of protractor for measuring distances on 13 not to be considered a complete substitute for examination of country itself 41 notes on, to state tacts and not orders 57 rarely up-to-date 55 emall scale, adding extra information to enlarge ment of 55 small scale, best procedure for enlarging .. 56 small scale, enlargang 55 small scale, use of 7 strategical, use of 7 uncontoared, failings of 42 Alarching by the stars, instruction 10 81 on a compass bearing at night 31 Margio, use of for giving information .. 85 Dlargh, how shown 18 Measure, unit of, the 12 Jeasures, foreign 83 Methods of finding one's position on a man 43 Memory sketching 61 Metnc system, countries in bich tiset 82 X2 Miles, dumber of to an incb, tu find 12 Mitary map, points to be shown on a 1 19 11 Vamce, correct spelliag of to be observed 85 of foreign torze, de, spelling of 58 Naming points on a sketch 85 Night, Line of advance by, indication of on the compass 30 marcbing on a compass bearing at 87 moonlight, use of a lumin. ous compass on a 31 prolongation of the line of advance at 32 march, method of selecting a star as a bearing for 81 marching, necessity for Terord of distances tr. versed in finding the line of advance 32 work, use of compass for 30 Noon, position of the sun at 40 North, magnetic, how marked on service prismatic compass 32 true, approxiniate methods of finding the 40 use of a watch for finding the 40 Notes, method of inserting in sketch 83 on maps to state facts and pot orders 57 ! 19 . 11 .. . 73 •40 .. ... 10 . 0. 19 system, the 59 Observation points, reference to in road reports Obstacles, beertion of in pano. rama drawings 79 ·99 11 . PAGE Oficers, regimental, subjects in which to be proficient 5 selected special instruc. tion of 5,8 Orders not to be contained in potes on mans 57 Ordnance Survey maps, conven. tional signs on Outpost sketcbes, abbreviations uscl in 19 . 99 P. ID PACE Plane-tablc sketch, rules to be observed in executing a 69 sketching .. 67, et seg tr.lversing 7 Plotting angles, method of 33 resection, method of Points, mutual visibility of 47 methods of determiding 86 ruling. use of in mapmaking 40 Pole star, true bearing of the Position, enemy's, reconnaissance of, with a view to attack 63 fizing by resection 45 on a map, to find 43 Positions of troops and works, #hen shown on a sketch 67 Primaries, use of 13 t'rinting company, R.E, capabilities of a 29 Printing, sc, Jirection of, on a sketch 85 Protractor, constructing scales without the use of a 11 scale of miles shown on the 33 scale of yards shown on the 33 service, description of thc 33 vse of, for drawing scales 13 nse of, for plotting and reading angles 33 use of, for reading bearing on a map or sketch ... 33 use of, to measure distances on iltary m28. 13 #Y Pacc, even, neccssity for practice in taintaining an 5t, footnote T'aces of the horne 5+ l'acing, use of tor measuring distances l'ant, luminous, we of 31 l'anorama drawing 74, et spl details to be included an 79 points to be olserval in executing a 76. ure use of shad. ing in value of, aan aljaat to a report 011 an artillery position 75 cuxution of 10 BC. tlous l'atrol, method of showing in must shetches 19 J'erspective, example of 18 rules regning 77 1'xquet, abbreviation for it out. 1*** *ketches 19 l'tane-table, descriptlun of the G Federal taxímy to te oletel 1 Brounting a moubts H 2. H Q. Quars Information regarding to Incluel in a river tacos. ta'sirs Tent . 81 ·PAGE 1 Tarix: report, written, value of a rough work a Tallway, how shere reconb16520cp, rnfor. mation to be 19claded in re. port of a Hipidity, value of in prodacing Itay, methorl of drawing when ueiog a plane table Inrs, method of taking leading in lcs mctbol of Recondageanec billetron, information required in re- Port of a defensive of an enemy's positor with View to attack railway, infermation to be included in Tepozt of a report infomation to be included 10 a river, information required roaci, information required la a sketches, size of scale for RF, definition of Regimental officers, subjects in which to be proficient Terort, reconnaissance, import. ance of distroguishing between facts and Learsay in a reconnaissance, informi. tion to be included in a road, use of raralry sketebing boan for making a sketch 201 addition to G Resection from three points 13 (plane-table sketch) 70, e kry from two points (plane-table sketch) 73 + methou of (planetable sketch) 70 method of plotting 14 49 process of use of for filling in detail (plane-table sketch) 70 ase of prismatic com- 08 p1c9 for 14 t) Reverse, abbreviation for, in outpost sketches 19 Rirer, information regarding, to be added to G3 sketeb 11 netbood of drawing a hech palesance informa. thou required an GO 61 Telocity of a, tethod of fuding the RO ISA, ose of the manual for cadets of the 5 DMC, ose of the manuil for 5 cadets of the ... 60 | Road, curves and bendis of, as shown on wall scule 46 53 maps details 13 metbol of drawing 12 particulars of to be notel reconnaissance, informa- 5 tion ncqmred in a report, use of cavalry sketching board for making a 59 Lule for express.ng as a gradient slope given in degrees 27 03 Rates for sketching, mountelor dismountel, with the cavalry setching board 63 55 Rules reganiing perspectie 71 1 1 &.. 11 ·$. f ! - Scale, extinple of method of expressing & 32 of miles slown on the protractor of minutes, method of drawing of yards shown on the protractor primary divrons in 13 sccoodary Pisions of B 1) P9 construction of Without the art of the mofractor 34, ef us icagth of MBC of protractor for drawing Healion drawing, use of instruction bouwons, execution of spora. Iraning in 76 Hervice company, descrieron x 37 - one of in a panorams) thriving 73 ght rule, excsiption of the Sign cosventional, se of 12 Sketch, fcul, fextures to Lw Lawn on a 3x3 back, we of 33 Improvisation of narr to klentily points on a soformation is turnem * from an orks to le 1 rua military, wentrals ng 18 Nane-table, rules ro 1 OLSEA esreutinga 63 rennance, scale for 12 rouges, value of us ad data to #written *31 1ceapolc, method of rotacing a Sterbes, tambient, Dribal of ifung PAGE Sletebes, execution of without 2Datromeata 021 field approret coaventsonal signs for 17 field, scale for use of finishing up for tactical scheincs 83 notes on finishing up outpont, abbreviations qsed in 19 Posts to be contained sa a Sletthing board, cavalry, use of 5t, et ne eye and memory C# fickt, het bod of showing hill features in 12 general prin ples of 4,2 mg 5114fruments carna? for od blank paper $ og blank paper, tegi mental ofbeetsto be anstructext 10 pape-table Wojx giren is degrees, rule for eepTL8NG H9 a gradient 25 Slopes, method of expressing 34 practicable for tracties engines meucable for licclesi rebicks ansform, convex nod cois mre, examples of use of clinometer for me23110 Small scale majx.entargomento 33 Southern Cross, use of for A. for the true orth 40 Spelling of tiamat of forcin to ng As. Spot level { Squate the surco (metrcantem) Equattt ux of fur enlunas bruary star. maila dettag *** karlog for a night maarch 67, I mea 1 11 ·102 PAGE Star, pole, true bearing of the 10 Stars, instruction la marcbing by the N1 wun, motion of at toon Supplies, reference to a reporte sopport, abbreviation for in outrost pictches 19 PAGE True north, approximate, methods of finding the 40 Tamming reference to in road reports 52 V. 34 T 62 11 25 Variation of compass, method of finding the Vebicles, reference to in report of a bulleting recunnaissance wheeled, slopes practicable for Velocity of a river, method of determing the View, choice of a point of, before commencing 2 Panorama tibility of porotx example of mutual of posts, mutual, rpethods of Jeter. 60 dring 19 2 מנוומ . W. Tactical information request in Arrad recamara 38 chimis, turbing up whetches for Tracing cloth use of 26 Technical terms, definitions of 9,807 Telescope, field, ac of 75 Telescopic shetch, techod of producing RU Tirae allowance of, for the conter 5+ for the trot for the wall (mounted) 64 measuring distances by 54 Topographical forms, definitions 8 information, add. tion of to a map 6 Traversing plane-table Dee of 10 map-making 30 when used (planetable sketcb) Triangle, error of 71 Trangulation, use of ih map. making 48 Trough-compass, the 67 Troops, method of showing 19 Trot, allowance of time for the 61 True bearing, examples of fine. 36 only to be quote 42 true bearings 36 54 TO 1) Walk, allowance of time for (mounted) Match, we of, for fiading the truc north Weather state of, to be recorucci on panorama dravogs IV histle, use of at bigbt in con. nection with the prolongation of the line of advance. Woods, information regarding to poted 80) . 19 log the Z. Zero of a scale where placel. 13

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·VOTE
Plates 5, 6, 7, 8, and 12, of the 1912 Edition
hare not been incluicul in this issue.
Plates 22, 23, 24, aut 2.5 hare been added

·CANADA
Martπιση
1
Rais!
Bonville
764
0
Grunt Corner
Glen
Donala
Comienil
Centre
r
Ble Norlirs
WALL
Barnie
ISLAND
CORTWACZ
Scale 120720 or 1 Inch to 2
hobune in the way ton
O
les
3
Canton
7 Biles

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·GERMANY
12
was
B
с
Seale sobo 10Miles to linen
Mite.
Mje.

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·Plotte 11.
FRANCE
A)
w
Dixong. I
I. INI, *. my w
Seuls by 179 Miles tai inch
Kilol___

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·IN NATURE
Plate 17
en wesente
villages
-10
Roads & Railways
PERMATA
111171
gs & Embankments
...ut.

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