The size of the aperture in the nave, both at the back and front of the wheel, should then be taken, they will generally be about 4in., tapering to 3in. or 2½in.; the length of the arm will probably be from 14in. to 16in. In cutting the arm nothing is to be tapered off from the front (Fig. 1) or from the lower part (Fig. 2), all the taper being cut from above and from behind, so that the wheels may incline a little inward in front and below, and if the axle arms should bend a little with the weight of cargo and with the forward draught, they may only have a tendency to resume a true position.
The arms should be carefully lined off in accordance with these rules, and in cutting the shoulder (Fig. 3) it should be squared, not from the edge of the axle, but from a line (dotted in the illustration) drawn along the centre of the arm, so that the back of the nave may bear truly against it. In cutting the shoulder be sure not to weaken the arm by letting the saw go, however little, beyond the proper depth, for where so great a pressure has to be borne the slightest cut would become the beginning of a fracture. When the arms have been cut and roughly rounded by saw and adze or axe, trim them with the spoke-shave, and occasionally try on the wheel, whirling it round to test the truthfulness of the work—there is almost sure to be sufficient grease or tar left in it to mark all the undue projections, and to leave clean the hollows on the arm, and the marks should be carefully examined that you may know what parts require to be trimmed away. It is now time to take off the iron work from the condemned axle; and sufficient notice should be taken of every piece, to know exactly to what portion of the woodwork it is to be restored, for much extra difficulty is occasioned by any uncertainty on this point. Bolts, though of the same apparent size, should not be transferred at random from one side to the other, and every nut, when once removed, should be scrupulously restored to the individual bolt it belongs to. These injunctions may seem needlessly strict; but we speak from experience, and if the reader has to attempt the work now under consideration he will do well to attend as strictly to them.
The iron skeins, or friction guards (Fig. 4), should be removed from the arms of the old axle and carefully let into the corresponding ones of the new; and when nearly fitted they may be slightly heated so as to char and smooth the bed for themselves, as well as to grip more tightly, in cooling, the wood they are meant to protect. Before fastening them with their proper bolts the wheels should be tried on to ascertain that they have been truly fitted.
Note.—The sketch above shows, on one side, the kap tent, or properly-built roof, and on the other, the wattled substitute. O is the front of the “kadel,” or swinging bed frame, L, 8, M, on the next page, are the yokes, skeis, and trek gear, drawn to the scale given at the side.
If, as is most frequently the case, the new axle is a front one, it must now be fitted under the rest of the fore “stell” or “carriage” (H), the holes for the connecting bolts and perch-bolt marked and truly bored, and the clamps which bind it to the upper portion heated, driven into their place, and tightened by being suddenly cooled with water.
Sometimes, when it is not necessary, or wood sufficiently large cannot be procured, to make a new axle, a new arm (I) may be let in, and this should be scarfed and checked in, and the inner end (Fig. 5), which reaches nearly to the centre of the axle, cut, not square, but diagonally across, so that the after side is somewhat longer than the front, and this, preventing the inner end from coming forward, will also counteract the natural tendency of the draught to force the arm backward.
