Hammocks.—­See section on “furniture.”

Coverlets.—­General Remarks.—­For an upper cover, it is of importance to an otherwise unsheltered person, that its texture should be such as to prevent the wind blowing through.  If it does so, no thickness is of any avail in keeping out the cold; hence the advantage of skin carosses, buffalo robes, leather sheets, and macintosh rugs.  All clothes lose much of their closeness of texture in a hot, dry climate; the fibres shrink extremely, and the wind blows through the tissue as through network.  It is in order to make their coverings wind-proof, that shepherd-lads on the hills in Scotland, when the nights are cold, dip their plaids in water, before sitting or lying down in them.  The wet swells up the fibres of the plaid, and makes the texture of it perfectly dense and close.  It is also of importance that the outer covering should have a certain weight, so as not to be too easily displaced, either by the person fidgeting in his sleep or by the blowing of the wind.  In dry weather there is nothing like furs; but in a rainy country I prefer a thick blanket bag (see “Sleeping Bags"), a large spare blanket, and a macintosh sheet and counterpane.  It may be objected that the bag and macintosh would be close and stuffy, but be assured that the difficulty when sleeping on mother earth, on a bitter night, is to keep the fresh air out, not to let it in.  On fine nights I should sleep on the bag and under the spare blanket.

Stuffy Bedding.—­It must be understood that while recommending coverlets that resist the wind, I am very far from advocating extreme stuffiness, and for the following reason.  Though a free passage of the wind abstracts an excessive amount of animal heat from the sleeper, yet the freshness of pure air stimulates his body to give it out in an increased proportion.  On the other hand, sleeping-clothes that are absolutely impervious to the passage of the wind, necessarily retain the cutaneous excretions:  these poison the sleeper, acting upon his blood through his skin, and materially weaken his power of emitting vital heat:  the fire of his life burns more languidly.  I therefore suspect it would be more dangerous to pass a very cold night enclosed tightly in thin macintosh buttoned up to the chin, than without it.  Much less heat would be robbed from the sleeper in the first case, but he would have very much less heat to spare.  There is, therefore, an intermediate arrangement of sleeping-gear, neither too stuffy on the one hand nor too open on the other, by which the maximum power of resisting the chill of the night is obtainable.

Sleeping Clothes.—­Some travellers prefer to have their blanket at once made up into a loose coat, trousers, and cap, pockets ad libitum, and a tape in the trouser band.  An extra suit is thus always at hand, the sleeper loses little of the advantages of comfortable bedding, and is always, in some sense, dressed for any emergency.