His observations should be expressed by written remarks, and by sketches. For this purpose he must be provided with a sketch book, on the right hand page of which, he may express the appearance of the country by sketches, and on the left, the remarks made on particular parts, with the names of the towns, their distances asunder, &c. with proper references to the sketches. The scale most proper for this purpose is two inches to a mile; if therefore, the sketch book be made six inches wide, and the leaves divided by lines into three equal parts, each division will be one mile, which will be a sufficient scale for the purpose. 1st. _Roads._—The principal points to be attended to in examining roads for military purposes, are, their direction; the villages, countries, and rivers, which they pass through; the roads which cross them; their names and the seasons in which they are in best condition; and if ever impassable, their breadth, whether variable or constant; their bottoms, of what principally formed; their ascents and descents, whether practicable for all kinds of carriages. The enclosures may be hedges, ditches, walls, or fences. If the roads require repair for the transport of artillery, and other heavy carriages, observe if the necessary materials are at hand. If they pass over rivers, remark whether by bridges or fords; if through marshes, whether by causeways or otherwise. If two or more roads pursuing the same route, and by which different columns may march, at any part join or cross each other, it will be necessary to observe, whether the march of the columns will be thereby impeded. If they only cross each other, it will be sometimes possible in hollow ways, to throw a temporary bridge across the deepest, by which one column may pass over and the other under the bridge, without interrupting each others march. 2. _Fords._—A ford for cavalry ought not to be deeper than 4 feet; for infantry not more than 3 feet. Observe the banks of the ford at each side; their form, steepness, and height; their situation as to the turnings of the river. Their bottom, whether passable for carriages. Observe marks by which the ford may be readily found; points from which it may be protected. Notice the rapidity of the water; whether its height be variable; its direction, its breadth, and the means by which the ford may be destroyed or rendered impassable. 3. _Inundations._—Learn the manner of working the sluices; the time in which the inundation may be effected; its extent and depth. Observe how the dam may be protected; its height and solidity; whether it can be easily raised, or easily destroyed; whether it is commanded by distant positions, and whether the inundation can be otherways drained. Notice the adjacent country.