216 
On Shading Mountain Land. 
[July, 
induced a scientific oflicer of high rank, a member of the Board, to express his 
regret that so much should be done upon a material, from which it was im- 
possible to multiply the copies by the press. The greatest care must be taken 
in military plans, to represent distinctly the different commands of ground ; to 
accomplish this, at Sandhurst, when a plan drawn by the brush is receiving 
its last touches, a light shade, or tint, which may be called a submitting shade, 
(as it submits, to use a military term, the lower to the higher levels,) is thrown 
over all the plan. Except the most elevated summits, its deepest tint, which is 
laid upon the lowest bottoms or valleys, is very light, but it is made to vary 
in degree for each level. In shading ground upon the principle, that the degree 
ot shade should be in an inverse ratio to the intensity of the light falling upon 
the spot to be represented, as is proposed by the Germans, we doubtless make 
a nearer approach to ideal perfection than in the method just mentioned, where 
all inclinations above 45° are blended in one undistinguishable shade of perfect 
blackness ; yet for military purposes this latter method is, as it is hoped the fol- 
lowing will prove, decidedly preferable. In the first place, every general officer, 
into whose hands a plan may be put, though able to read an ordinary map, and 
to understand that the stiffer lines are roads, the more waving, rivers, and that the 
dark blots are hills, yet is not to be supposed conversant with all the details of 
surveying and topographical delineation. In looking at his plan, and finding 
a hill shaded with tour paits of ink, to six of water, and consequently sufficiently 
pale, he might veij possibly suppose that it would be perfectly accessible to troops 
ot all arms, and to save the time which might be lost in a detour : think himself 
quite safe in ordering a body of cavalry to pass over it ; he would be much surprized, 
on coming to the spot, to find a steep precipice, having an inclination of 53° much 
more steep than any unrivetted rampart, present itself, and practicable only for 
goats or jagers. 
In a plan, executed in the Sandhurst method, .such an inclination would be deli- 
neated m perfect blackness, put on brokenly, to represent the jagged projections of 
econdly, in nature we find none but the stiffest soils take natti* 
y a slope so steep as 45°, on which account this is the steepest slope used in 
constitution of permanent earth-works; any slope more steep than 45°, be- 
comes a precipice, and will be found almost invariably to consist of bare, oral* 
os are rock.. Thirdly, all plans fade. As a plan becomes old, and has 
ort time m use, the white parts of it become discolored and darkened ; the 
pale shadings will fade; therefore, the light tints used to represent the declivities 
. . , . ’ m 1 le 9 erman met hod, would become almost inappreciable. In making 
i . j ectlon ’ lt; ls not to be inferred, that the Cimmerian style is advocated; in' 
toTblae e k"°r i0 , neSt faUlt With y0Un S draughtsmen is, the making their plans 
eivins- effert * eS ^ aspilin S Rembrandts, thinking that there is no possibility of 
LJl hm\a/ T ng the extremes 0f black and w hite, make the smoothest 
f, , s and forth in all the grandeur and ruggedness of rock and precipice- 
f excessive blackness be intolerable, objections equally lie against the other 
extreme ; a medium must beheld between the two, and a plan must be shaded 
™ SUffi r t f Pth t0 be diStinCt * Fourthl y> by making the maximum shade to 
present 4o of inclination, the variation in denth of tint between the different 
w s, objections equally lie against me < 
Si L " ‘ mU3t bC lleM between the two, and a plan must be si 
r depth to be distinct. Fourthly, by making the maximum aha, 
piesent 45 of inclination, the variation in depth of tint, between the differ™- 
t‘ t a t dtCbv becomes more easily appreciable, particularly to the uniui 
n an atteill l )t to reduce the method, having the maximum shade at 45 , t0 
tl * ounded u P on a theory, arising from the actual illumination of the ground, 
in ° -° Wmg lme ° f reasonin & was tri ed ; that the degree, or depth of shade, be 
rse ratio to the intensity of the light reflected from a given spa ce u P° a 
