To preserve iron from rusting.
Iron which has become deeply rusted cannot be platinised by our process. In order, however, to preserve from further destruction objects of steel or iron having an archæological or artistic interest, a very excellent plan may be used as a substitute. The purest white paraffine is to be melted in a clean pan, and maintained at about the temperature of boiling water. The rusted and corroded specimens are to be immersed in this paraffine bath till they cease to froth from escape of moisture. They are then withdrawn, wrapped in blotting-paper, and kept in a warm place till the excess of paraffine has been absorbed. The objects thus treated, while preserved from further decay, do not acquire that disagreeable greasy aspect which the varnish ordinarily used imparts. We have been obliged to tar our saw blades, which was very inconvenient in working, but this was better than having them spoiled by rust.
Smith’s tools.
If the traveller has a waggon, as in South Africa, he may either carry a portable forge or trust to finding natives capable of building one and supplying bellows of their own manufacture. If he thinks the weight of a small anvil too great, he should carry a heavy sledge hammer, which will serve as an anvil for ordinary purposes; two hand hammers of different weights; half-a-dozen pair of tongs, of such form and size as will enable him conveniently to hold the different sizes of work he may find necessary to do; at least a dozen files or more—square, flat, half-round, or rat-tail; and of these the temper should never be destroyed by working with them on iron that has not yet become cool, though occasionally time may be saved by using a worn-out file to work on iron while it is yet hot and comparatively soft; cold chisels of different sizes, from small ones of 1/4in. or ½in. wide, to be tapped with a small hand hammer, to others of 1½in., to be held by pieces of rod iron coiled round them, or still better by rods of osier, and to be struck with the sledge hammer; if there is an anvil, of course a chisel to fix upright in the hole provided will be taken with it; punches of various sizes, and a stock and set of drills for boring holes up to ½in. in diameter, with rymers, or tapering four-edged tools for gradually enlarging them, and countersinks for letting in the heads of screws, &c., to the surface level. For small work, such as gun-locks, &c., an Archimedean drill and set of bits are very convenient, a hand-vice and set of gunsmith’s small files—triangular, square, flat, half-round, round, and knife-edged—should accompany them.
Muskets, to repair.
A traveller will frequently have occasion either for his own servants or for the natives of the country to put “fresh fire” into the pan cover of a musket; for this purpose nothing is better than the blade of an old saw, the thinner the better; a piece is broken off, softened and filed down to the exact size; it is then bent so as to fit the face of the pan-cover, and is bound on to it by several turns of iron wire, not drawn so tightly but that bits of copper wire may be thrust beneath them all round the edges that are to be joined; borax, dissolved in water, is now laid on with an old brush, and, if necessary, small lumps are also added, and the whole is placed in the fire and heated till the copper melts and brazes the two parts firmly together; let it cool slowly, finish it carefully with the file, heat it to a dull red, and temper by cooling it in water. Half-civilised Hottentots frequently do this.
Fish-hooks, to make.
The snoek-hook used in Table Bay is a bit of brass wire as thick as a quill and 7in. long; the point is filed sharp, and the barb is merely such a triangular notch as might be made with a handsaw file. It is not bent in a true sweeping curve, like our fish-hooks, but turned sharply up at about 2in. from the point, so that when the lip is pierced, it slips at once into the sharp bend of the hook, and the struggles of the fish are less likely to break it than they would be if it afforded the leverage that the usual form of fish-hook gives. (See Fig. 20, p. 211.) Fish-hooks can be made by taking a wire or rod of the required size and softening it by heating it to a bright red and letting it cool very slowly in sawdust or leaving it till the fire dies out; let the soft end abut against something solid, and, with a sharp chisel and mallet, make a deep cut at such an angle as to form the barb; file up the point, heat it again, and bend it round a stick of the proper size so that the curve may be true. We have, before now, broken up a gridiron at the galley fire, and with a hook thus formed from one of the bars caught a young shark, whose flesh formed a very desirable addition to our fare. On another occasion, while exploring a branch of the Victoria River, in North Australia, we halted, as usual, at noon, with scanty rations, which Mr. Gregory improved by taking from his hat a stout sewing needle, softening it in the fire, and bending it into a fish-hook, baited with grasshoppers; a few strands of thread made a sufficiently strong line, a small sapling formed a rod, and, in a few minutes, he had caught three fish, resembling mullet, nearly 18in. long. The needle had done good service, but was too precious to be thrown away, so Mr. Gregory carefully restored it to its pristine straightness, tempered it, and again stuck it in his hat, to be used, when required, for its legitimate purpose.
Brass, and its treatment.