The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking. Paul N. Hasluck
the head, till at its entrance into the head it may be double what it is at the other extremity. It often has also a projection at the extremity of the handle. The increasing thickness near the head gives strength where needed as the axe is being driven in. There is, too, this further difference—in a sledge-hammer more or less recoil has to be provided for, and the handle does this; in the axe no recoil should take place. The entrance of the axe edge is, or ought to be, sufficient to retain it, and the whole of the energy resulting from muscular action and gravity should be utilised. The curvature, too, of the handle is in marked contrast with the straight line of the sledge-hammer handle. The object of this curvature is worthy of note. The handle of an American forester’s axe is very long and curved. In sledge-hammer work the face is to be brought down flat, that is, as a rule, in a horizontal plane, whereas the forester’s axe has to be brought down at varying obliquities. If, now, the hewer’s hand had to be counteracting the influence of gravity, he would have much needless labour; hence the care of a skilled forester in the balance of the axe-head and the curvature of the handle.
Fig. 344.—American Adze.
THE ADZE.
The variety in the shapes of adze-heads is very great, there being two or three kinds used by each of the following:—Carpenters and joiners, ship carpenters, wheelwrights, and coopers. The carpenter knows three principal varieties, the English pattern (Fig. 342), Scotch pattern (Fig. 343), and American pattern (Fig. 344). The ash handles used with these may have either of the shapes illustrated by Figs. 345 and 346. The adze must be sharpened from the inside, and when its action is considered (see next paragraph), it is clear that the curvature of the face of the adze-iron must be circular, or nearly so. The true curvature of the metal may be approximately deduced from considering the radius of the circle described by the workman’s arms, and the handle of the adze. The edge of the adze is slightly convex for the same reasons as influenced the curvature of the axe edge already alluded to (see p. 92). The curvature in the blade also serves (though partially) as a fulcrum, for, by slightly thrusting the handle from him, the workman may release chips of timber beneath which the adze is lightly embedded.
Fig. 345.—Adze Handle.
Fig. 346.—Adze Handle.
Fig. 347.—Plain Handle London Screwdriver.
HOW TO USE AN ADZE.
The general method of using the adze is as follows:—The workman stands with one foot upon the wood in the line of the fibre, and thus assists in steadying the work. The long handle of the adze is curved so as to permit of an efficient blow being given, and the tool brought to a stop before the handle strikes any part of the workman’s body; it is caused to stop by the exhaustion of its impact energy in the fibres of wood. The adze is raised by both hands until nearly horizontal, and then not allowed simply to fall, but steadily driven downwards until the curved metal, with its broad and sharp edge, enters near to, if not below the sole of the workman’s shoe, separating a large chip of wood from the mass; the handle is rapidly raised, and the blows are repeated quickly, the workman gradually drawing back his foot until the end flakes of wood are separated. The edge of an adze often is so keen as to cut through a horsehair pressed against it. It is not pleasant to contemplate an error of judgment or an unsteady blow, but practice brings great skill in the use of this tool. The Indian workman uses the adze for producing curved surfaces, and holds the tool so near its head that the hand touches the metal, the blows being delivered chiefly from the elbow.
Fig. 348.—Oral Handle London Screwdriver.
SCREWDRIVERS.
A description of screwdrivers in this chapter may seem out of place, but as they are tools of impulsion, even as is the hammer, they may fitly be dealt with here. Two or three screwdrivers at least will be required, long and short, and with wide and narrow blade. For general work, a tool of medium length should be obtained, although there are on the one hand enthusiastic advocates of a short tool, and on the other hand of a long tool for any and every purpose. Any advantage gained by a short over a long tool, or the reverse, is one of advantage in special circumstances only, and not one of saved energy; theoretically, the length does not enter into consideration at all, except when, in starting to extract a difficult screw, the driver is tilted from the upright, but this is at the risk of a broken tool edge and defaced screw-head. The worker then must decide for himself what sizes will best suit his purposes. The principal patterns are illustrated here. Figs. 347 and 348 are the London patterns, the, former with handle of beech or boxwood, and the latter with an oval ebony handle. Cabinet screwdrivers are shown by Figs. 349 to 351, Fig. 349 having a plain beech handle, Fig. 350 an oval boxwood handle, and Fig. 351 a fluted or “firm-grip” boxwood handle. For special work, it is necessary to have a long spindle-blade screwdriver, as shown by Fig. 352. The power gained by a screwdriver in turning a screw depends entirely on the diameter of its handle, quite irrespective of the length of its blade. Taking two screwdrivers having blades of the same length and breadth, but one A having a handle one-half again as broad as that of the other B, then A will turn the same size of screw as will B with exactly one-third less power expended; it is purely a question of leverage, and quite independent of the length of the blade. Of course, in correctly proportioned screwdrivers the longer blades generally have the wider handles, but it is not always so, and the increased length of the blade is usually disadvantageous except as already noted. An important point in working with large screws is to see that the point of the blade fills the entire width of the slot in the screw-head. A useful screwdriver is the one illustrated by Fig. 353. The handle is that of a gimlet, and can be separated from the blade, a great convenience for carrying, although the whole tool is only 6 in. long. In the handle are two hardened steel pawls acting on a ratchet, so that in driving a screw the right hand never moves off the handle, the left being thus at liberty to guide the screw. Reversing the handle on the tang of the blade puts the ratchet in position for withdrawing a screw. The handle is 4 in. long, which gives it, theoretically, great mechanical power. Practically, the advantage over the ordinary form is more than it is theoretically, as owing to the shape of the handle the power is better applied. Another very convenient form of screwdriver is shown in use by Fig. 354, and consists of a screwdriver bit (