It will be seen that the saws in this group are progressively smaller and finer. The rip-saw has the coarsest teeth, and which are of slight pitch, or mid-way between the upright or cross-cutting teeth, fig. 643, and those of ordinary pitch, fig. 645; the half-rip is similar, but a little finer; these two are used in carpentry for ripping or cutting fir-timber rapidly with the grain.
The hand and fine-hand taws are somewhat liner in the teeth, which are of ordinary pitch, or the face of the tooth is perpen-dicular; the hand-saws are much used by the joiner for ordinary purposes, and also by the cabinet maker, for cutting mahogany and other hardwoods with the grain.
panel and fine-panel are still finer saws of the same kind, which probably derived their name from baling been made for cutting out panels, when oak and other wainscotting were more common in our houses than plastered walls; and they may considered as intermediate between the handsaw, by which most of the work is done, and the tenon or hack-saw hereafter to be described.
The same workman does not require each of the six saws, but commonly selects the two or three most suited to his particular class of work; they are principally used for still further preparing the woods to their several purposes after they have been cut at the sawpit into planks and boards. The outlines of the works are marked out upon the surface of the plank by aid of the rule, passes and chalk line, or the straight edge and square, with much greater facility than setting out the round timber into planks, which has been already explained. The board baring been marked, is rested upon a sawing stool or trestle, the height of which is about 20 inches; if the work be long two stools are employed. The workman commonly places his right knee upon the board to fix it, and applies the saw on the portion that over-hangs the cud of the stool.
The saw is grasped in the right hand, and the left is applied to the board, in order that the end of the thumb may be placed just above the teeth and against the smooth blade of the saw, to guide it to the line; the saw is then drawn backwards a few inches, with light pressure, to make a slight notch, a short gentle down-stroke is then made almost without pressure. In the first few strokes, the length and rigour of the stroke of the saw are gradually increased, until the blade has made a cut of two to four inches in depth; after which the entire force of the right arm is employed, the saw is used from point to heel, and in extreme cases, the whole force of both arms is used to urge the saw forward. The blade is occasionally greased to lessen the friction, the end of a tallow candle being mostly used, or else hog's lard smeared on a piece of thick leather.
In most instances little or no pressure is directed edgeways, or on the teeth; and when the effort thus applied is excessive, the saw sticks so forcibly in the wood, that it refuses to yield to the thrust otherwise than by assuming a bow or curved form, which is apt permanently to distort the saw from the right line. The fingers should never be allowed to extend beyond the handle, or they may be pinched between it and the work.
In order to acquire the habit of sawing well, or in fact, of performing well most mechanical operations, it is desirable to become habituated to certain defined positions. Thus in sawing, it is better the work should, as often as practicable, be placed either exactly horizontal or vertical; the positions of the tools and the movements of the person will also be then constantly either horizontal or vertical, instead of arbitrary and inclined.
In sawing, the top of the sawing stool should be horizontal, the edge of the saw should be exactly perpendicular, when seen edgeways, and nearly so when seen sideways; the eye must watch narrowly the path of the saw, to check its first disposition to depart from the line set out for it. If however, the eye be directed either so far from the right or left side of the blade as to form a material angle with the line of the cut, the hand is liable almost uuconsciously to lean from the eye, and thence to incline the saw sideways. It is therefore best to look so far only on the right and left of the blade alternately, as to be just able to see the line, and thence to detect the smallest deviation of the instrument at the very commencement of its departure. And then, by twisting the blade as far as the saw-kerf will allow, the back being somewhat thinner than the edge, the true line may be again returned to; indeed, by want of caution, the saw may be made to cross the line and err in the opposite direction. It is however, best to make it a habit to watch the blade so closely as scarcely to require any application of the correctional or steering process at all. The saw, if most set on the left side, or having teeth standing higher on the left side, cuts more freely on that side, and has a tendency to run or arcuate towards the left; and under the reverse circumstances the saw is disposed to run to the right.
Thick works are almost always marked on both sides the plank, and the piece is turned over at short intervals, so that a portion of the work is performed from each side; the saw-cut will then assume a series of slight bends, to the right and left alternately, and will depart less from the true line, than if these disturbances had effect from the one side only, and thus produced an accumulating error, or a line swerving in one direction alone, or as a sweep of a large circle. The practice of changing sides with the work will, under most circumstances, be found to lessen the errors incidental to the process, and the practice is therefore especially desirable for beginners.
The work is not always placed on the sawing-stool, as in some cases it is laid on the bench, and fastened down upon the same with the holdfast or band screws, and with the intended cut situated beyond the edge of the bench; the workman then stands erect, and uses the saw with both hands, placing the back of the saw towards his person, and sawing from it; this with many is a favourite position. In some cases, especially in small and thick works, the wood is fixed perpendicularly in the screw-chops of the bench, and the saw is applied horizontally. These modes are both good, inasmuch as they relieve the individual from the necessity for holding the work with the knee, and he is less restrained in the action of the limbs.