Substitutes for glass.--These are waxed or oiled paper or cloth, bladder, fish-membranes, talc, and horn. (See "Horn.")
SLEEPING-BAGS.
Sleeping-bags.--Knapsack Bags.--These have been used for the last twenty-five years by the French 'douaniers', who watch the mountain-passes of the Pyrenean frontier. The bags are made of sheepskin, with the wool inside. When not in use they are folded up and buckled with five buckles into the shape of a somewhat bulky knapsack (p. 152), which the recent occupant may shoulder and walk away with.
The accompanying sketches are drawn to scale. They were made from the sleeping-bag belonging to a man 5 feet 6 inches in height; the scale should therefore be lengthened for a taller person, but the breadth seems ample. Its weight was exactly seven pounds. The douaniers post themselves on watch more or less immersed in these bags. They lie out in wet and snow, and find them impervious to both. When they sleep, they get quite inside them, stuff their cloaks between their throats and the bag, and let its flap cover their faces. It is easy enough for them to extricate themselves; they can do so almost with a bound. The Spanish Custom-house officers who watch the same frontier, use their cloaks and other wraps, which are far more weighty, and far inferior in warmth and protection to the bags. I described these knapsack bags in 'Vacation Tourists for 1860,' p. 449, and I subsequently had a macintosh bag lined with drugget, made on the same principle. I had a hood to it, and also the means of buttoning it loosely under my chin, to make myself watertight during heavy rain. In that bag I passed many nights of very trying weather. On one instance, I selected a hilltop in Switzerland, on the way from Chambery to the Dent du Midi, during a violent and long-continued thunderstorm. The storm began above my head, then slowly sank to my level, and finally subsided below me. Many Alpine travellers, notably Mr. Packe and Mr. Tuckett, have adopted these bags, and used them continually. Macintosh is certainly oppressive to sleep in, though less so than might have been expected, as the half-unconscious fidgeting of the sleeper changes the air. A man in travelling "condition" would probably find a drugget-bag more healthy than macintosh, even though he became somewhat wet inside it. Beds used to be almost unknown in some parts of the Pyrenees. Sheepskin sleeping-bags were employed instead. Thus, I am assured that at the beginning of this century, there was hardly a bed in the whole of the little republic of Andorre. The way of arranging them as knapsacks is, as I have said, a recent invention.
In fig. 1 the wide opening to the mouth of the bag is shown; also the ends of the buckles and straps that are sewn (on patches of leather, for additional strength) to the lower side of the bag, as seen in fig. 2.
It must be understood that the woolly sides of the skins are inwards. The straps that hold the knapsack to the shoulders are secured by a simple fastening, shown in figs. 2 and 3. But the ordinary knapsack hooks and rings, if procurable, would answer the purpose better. The straight lines in fig. 1 show the way in which the bag is to be folded into the shape of fig. 3. Fig. 4 shows the sleeper inside his bag, in which he fits very like a grub in its cocoon. There is no waste of space. For the sake of warmth, the bag is made double from the knees downwards, and also opposite to the small of the back.
