To make a mould for a pencil, or a rod which may be cut into short lengths for slugs, roll up a piece of paper as shown in fig. 2, and bury it in the earth: reeds, when they are to be obtained, make a stronger mould than paper.
To cast a lamp, a bottle, or other hollow article, use a cylinder of paper, buried in the ground, as in fig. 3, and hold a stick fast in the middle, while the lead is poured round.
Loose, shaky articles often admit of being set to rights, by warming the joints and pouring a little melted lead into the cracks.
Tin.--Solder for tin plates, is made of one or two parts of tin, and one of lead. Before soldering, the surfaces must be quite bright and close together; and the contact of air must be excluded during the operation, else the heat will tarnish the surface and prevent the adhesion of the solder: the borax and resin commonly in use, effect this. The best plan is to clean the surfaces with muriatic acid saturated with tin: this method is invariably adopted by watchmakers and opticians, who never use borax and resin. The point of the soldering-tool must be filed bright.
Copper, to tin.--Clean the copper well with sandstone; heat it, and rub it with sal-ammoniac till it is quite clean and bright; the tin, with some powdered resin, is now placed on the copper, which is made so hot as to melt the tin, and allow it to be spread over the surface with a bit of rag. A very little tin is used in this way: it is said that a piece as big as a pea, would tin a large saucepan; which is at the rate of twenty grains of tin to a square foot of copper.
LEATHER.
Raw Hides.--Dressing Hides.--Skins that have been dressed are essential to a traveller in an uncivilised country, for they make his packing-straps, his bags, his clothes, shoes, nails, and string, therefore no hide should be wasted. There is no clever secret in dressing skins: it is hard work that they want, either continual crumpling and stretching with the hands, or working and trampling with the feet. To dress a goat-skin will occupy one person for a whole day, to dress an ox-hide will give hard labour to two persons for a day and a half, or even for two days. It is best to begin to operate upon the skin half an hour after it has been flayed. If it has been allowed to dry during the process, it must be re-softened by damping, not with water--for it will never end by being supple, if water be used--but with whatever the natives generally employ: clotted milk and linseed-meal are used in Abyssinia; cow-dung by the Caffres and Bushmen. When a skin is put aside for the night, it must be rolled up, to prevent it from becoming dry by the morning. It is generally necessary to slightly grease the skin, when it is half-dressed, to make it thoroughly supple.
Smoking Hides.--Mr. Catlin, speaking of the skins used by the N. American Indians, says that the greater part of them "go through still another operation afterwards (besides dressing), which gives them a greater value, and renders them much more serviceable--that is, the process of smoking. For this, a small hole is dug in the ground, and a fire is built in it with rotten wood, which will produce a great quantity of smoke without much blaze, and several small poles of the proper length stuck in the ground around it, and drawn and fastened together at the top (making a cone), around which a skin is wrapped in form of a tent, and generally sewed together at the edges to secure the smoke within it: within this the skins to be smoked are placed, and in this condition the tent will stand a day or two, enclosing the heated smoke; and by some chemical process of other, which I do not understand, the skins thus acquire a quality which enables them, after being ever so many times wet, to dry soft and pliant as they were before, which secret I have never seen practised in my own country, and for the lack of which all our dressed skins, when once wet, are, I think, chiefly ruined." A single skin may conveniently be smoked by sewing the edges together, so as to make a tube of it: the lower end is tied round an iron pot with rotten wood burning inside, the upper end is kept open with a hoop, and slung to a triangle, as shown in the figure.
