In the first place, it may be laid down as an absolute rule, that tents with single “flies” or roofs, are quite unsuitable to any climate, and should never be used except under the absolute compulsion of restricted transport. Such tents are insufferably hot in warm climates, bitterly cold in chilly ones, and damp and unwholesome in rainy weather in either. On the other hand, the use of waterproofed material is, as a rule, a mistake, and should at any rate never be adopted for the inner fly, as to do so would make any tent of moderate dimensions intolerably “stuffy.” In very rainy climates, there might be no harm in selecting light milrained canvas as the material for the outer fly; but there is no real necessity for this, as a tent should be so planned as to throw off the water by virtue of the slope of the roof, and not by the character of its materials.
A second point to be remembered, is that two or more layers of comparatively light material will afford far greater protection against either heat or cold than the same weight of material woven as a single heavy cloth, and on this account the canvas universally used in Europe for work of this sort is absolutely unsuited for the purpose.
Each fly of an Indian tent is usually formed of two or three layers of cloth, the outer layer being formed of what is generally known as “American” cotton drill, though it is usually of local manufacture; and it would be hard to find a material better suited for the purpose. Where only two layers of cloth are used, the inner layer should be a deep red, as this colour cuts off the largest proportion of the chemical rays of the sun, which exercise such a powerful effect on the human economy. With three layers the middle one should be red, and the undermost deep indigo. In the case of the inner fly, for the middle layer of cloth, where there is one, a deep red should also be selected, but the inner lining should be a pale yellow chintz, as a sombre cloth makes a tent uncomfortably dark. The poles should be so constructed that a space of free air, of not less than a foot, should intervene between the two flies, even in the smallest tents, and if the outer fly be properly planned, it should be impossible for rain to reach the inner fly, even under the worst conditions of weather; though this proviso need not extend to verandahs and bath-rooms, which are not intended for prolonged occupation, and so may be formed by the outer fly only. When weight is a serious consideration, as in the case of exploring parties, it would be difficult to find a better form than that known as the “Kabul tent,” which, with poles, mallet and pegs, weighs but 80 lbs., while the somewhat larger “Field Officer’s Kabul,” weighing, with verandah and bath-room complete, 120 lbs., forms about as comfortable a little residence as can be desired for such purposes. For Indian family use, and for permanent encampments, where a tent has to serve in place of a house, the best form is probably that known as the “Swiss Cottage Tent,” which, however, weighs, according to size, from 4 to 6 cwt., and is therefore only useful for a moving camp, where ample wheeled transport is available.