Where the transportation is inadequate as on a hike trip, the wearing of an extra suit of underwear is as warm as an extra blanket. One then gets the dead air space between the wool and the warmth is thereby intensified because the number of layers of covering retains the heat longer than one thick layer of the same weight.
In Arctic work the clothing and bed cover must be chosen with one particular fact in mind—that moisture condensation from the body perspiration or from accidental immersion in water must be eliminated, otherwise ice will form to the detriment of the individual. Any woven fabric will hold condensation while fur will not. Fur then is the clothing and bed cover of choice where one is exposed to extremes in cold. The fur should be worn with the hair outside the same way that the animals wear it, otherwise it is too hot. The best fur is caribou skin and it is warmer and lighter than a blanket of wool. Llama wool is next best.
Very satisfactory fur robes may be made of the rabbit or cat skin and if made after the following method you will have the warmest bed fabric known to man. The skins are tanned by soaking the “green” hides in running water for one to four hours. Then the flesh and fat is peeled off with a dull knife and the skin soaked for two days in a tan liquor of sulphuric acid (poison) one ounce, salt one quart and water one gallon contained in an earthen jar. Rinse the skin in clear water, dry and when partly dried work well in the hands thus breaking up the fibers to keep it soft.
The tanned and softened skin is now cut into long strips one-fourth of an inch wide, which are tied or sewed together, each strip being twisted so that the fur stands out all around the hide thong. These strips are then interbraided into a loose web in a frame the size your blanket is to be. The chief objection to this article is that it is heavy and the fur sheds a good deal so it is best to cover the blanket with light cloth which of course adds some weight without giving any additional warmth. A full sized rabbit robe weighs ten pounds and is warmer than many blankets of wool. The secret of its warmth is the dead air interspaces between the fibers.
There is considerable difference of opinion among woodsmen regarding the choice between the sleeping bag and blanket bed. There are good arguments for and against. As usually made a sleeping bag consists of two parts:—(1) a cover for protection from rain, dampness, and wind, and (2) a warm lining to retain body heat. To its credit may be enumerated these facts: Being sack-like the sleeping bag retains the heat within and keeps the cold out. It is easy to unroll, keeps out dirt and wind and the contents may remain dry and one has full protection in any kind of weather.
The objectionable feature is that the bag cannot be drawn up closely to the body and the resulting air space is difficult to warm up. It is hard to adjust the top to keep the air from the sleeper’s shoulders and the inevitable twisting and turning of the sleeper bunches the blanket up around the limbs.
A sleeping bag really is no substitute for a roof overhead on a rainy night as alluring advertisements would lead you to believe. Its waterproof cover retains inside moisture from the air and the body exudations of the sleeper thereby adding appreciably to the blanket’s weight. Thus a waterproof cover is no more wholesome to sleep in than a rubber boot is wholesome for one’s foot. In ordinary weather the sleeping bag is too hot and in chilly weather it is not as warm as it is supposed to be. Its narrow shape makes it difficult to crawl into the head end and it is very inconvenient should one need to get up several times a night to fix a night fire.
It is an unpleasant trap to be in when a squall springs up suddenly at night or the tent catches fire. No less famous an explorer than Peary discarded the sleeping bag for the reason that, aside from its being a weighty extra item of outfit, when sleeping in snow igloos he was in constant danger of a break in the icy floor from the formation of pressure ridges and if encumbered in the bag he would have extricated himself with difficulty. Quoting Mr. Harry Whitney—“On my winter ox hunt I started into the Barren Grounds with a bag of caribou and lined with rabbit skin—the very warmest robe possible, but I ripped it open before I had been on the road three days.”
The choice between a loose blanket bed and the sleeping bag is a matter of individual preference. If the latter is chosen it should be made to air easily and be easy of adjustment to varying temperatures. The permanently closed bag is out of the question as it retains the accumulated condensed body moisture. The only kind worth considering is one which can be easily opened and spread wide apart in the sunlight or before a fire every morning. The bag should be closed on all sides as far up as the breast of the sleeper and the continuation of the bag in the shape of a flap which can be nicely tucked about the shoulders.
Probably the best low temperature sleeping bag is of caribou skin with the hair inside. One lined with llama wool duffle is next best. The so-called Arctic or Fiala sleeping bag is the lightest one available from outfitters in the United States. If one prefers this kind of a bed the tramper can find nothing so excellent where the greatest amount of warmth with the lightest possible weight is imperative.