The difficulty with the sleeping bags on the market is that they are made for gentlemen campers, and not for those who take up their beds and walk. For one thing, the gentleman camper has abundance of clothing, with changes of all kinds. But the pedestrian sleeps in his clothes. Of course he does. It would be folly for him to carry in his pack the equivalent of what he wears on his back. His day clothes should be serviceable as night clothes, too. All he need carry is the additional protection required when he is resting on the ground in the colder night hours. And, in addition, he will have a change of the garments which lie next his skin; but no more. If when sleeping a man is not wearing all that he carries, then he is carrying more than is necessary. He may, indeed, have stuffed in his pack woolen underclothes, for night wear only. For another thing, in making choice between one material and another, the weight of the material is important in far greater degree to the walker than to the gentleman camper. With these considerations in mind, the pedestrian contrives his sleeping bag of the lightest material available to serve the ends in view.
Essentially, a sleeping bag is a closed covering of two layers: an inner layer of heat-insulating material, and an outer layer of water-tight, wind-tight material. Even the gentleman camper, scornfully referred to above, chooses the lightest, warmest blankets he can find; the pedestrian can do no better. However, he does not take so many. But, respecting the outer covering, the pedestrian refuses the heavy water-proofed duck of the ordinary sleeping bag, and selects instead water-proofed balloon silk.
The simplest sleeping bag may be made by folding a six by six wool blanket within a cover of water-proofed balloon silk and sewing together the bottom edges, and the side edges, too, from the bottom upward, to within a foot or so of the top. The bag measures approximately three feet by six, and should not weigh more than five and one half pounds.
Instead of the blanket, other material may be used. Men differ in the amount of covering they require; and then there are the inequalities of climate and season to be reckoned with. A suitable material, lighter than wool and affording less warmth, is sateen; a somewhat warmer, somewhat heavier, substitute for the wool blanket is a down quilt. When still greater warmth is needed the blanket may be double, or blanket and down quilt may be combined.
A rectangular bag, such as that just described, may be criticized in two particulars: for one thing, it is not long enough for a man of good stature, and, for another thing, there is waste material in it. It would be just as warm and just as serviceable if, instead of being three feet wide at the bottom, it were at that point only two feet wide.
The specifications of an excellent sleeping bag for pedestrian use are given in a pamphlet published by the Appalachian Mountain Club, “Equipment for Mountain Climbing and Camping,” by Allen H. Bent, Ralph Lawson, and Percival Sayward, and with the courteous assent of the designers, are here incorporated.
A bag made on the dimensions given is suitable for a man five feet eleven inches tall.
A strip of the material for the inner layer is cut to the pattern indicated below. It is 87 inches long, and at its widest point 32½ inches across. The widest point is 45 inches from the foot. At the foot the strip is 20 inches wide, and at the head, 21 inches. The sides are outwardly curved. This is the under strip.
