of 11 oz. in 24 hours. 'Therefore the heat given out by two candles is just about the same as that given out by one man, either in a sensible form, or else under a latent form by the vapour of the breath. Secondly, I have frequently heard it estimated, as the result of the ordinary experience of social life, that a saloon is warmed by each couple of candles somewhat more than it is by the presence of a single guest. Where I write these lines, I have not an opportunity of verifying my rough estimate, by reference to physiological works, but accuracy is of little consequence to my present purpose, which is to give a general idea of the magnitude of the problem to be solved by clothes and tenting. Their joint office is to retain the heat of a mass of flesh and blood, the size and shape of a man, warmed by two candles burning within it, at a temperature of not less than 96° in its inward parts.
Mattresses and their Substitutes,-A Strip of Macintosh.-If a traveller can do so, he should make a point of having a strip of macintosh sheeting 7 feet by 4, certainly not less than 6 feet by 3, to lay on the ground below his bedding. Every white servant in the expedition ought to be furnished with a strip of macintosh sheeting, or, failing that, with a strip of painted canvas. However, painted cloth is much inferior to macintosh, as it will not fold up without cracking : it also tears easily, and is heavy. Macintosh, of the sort that suits all climates, and made of linen, not of silk, is invaluable to an explorer, whether in the form of sheeting, coats, water-bags, swimming-belts, or inflatable boats. A little box full of the composition for mending it, and a spare bit of macintosh, should always be taken.
Matta•ess.-Making a mattress is indeed a very simple affair. A bag of canvas, or other cloth, is made of the size wanted. It is then stuffed full of hair, wool, dry leaves, or cotton, and a strong stitch is put through it every few inches. The use of the stitching is to prevent ent the stuffing from being displaced, and forming lumps in different parts of the bag.
Palliasse.-Straw, well knitted or plaited together, forms a good mattress, commonly called a palliasse.