The proper length of a yew bow should be the height of the man that shoots it, or a trifle less. Our hunting bows are from five feet six inches to five feet eight inches in length. The weight of a hunting bow should be from fifty to eighty pounds. One should start shooting with a bow not over fifty pounds, and preferably under that. At the end of a season's shooting he can command a bow of sixty pounds if he is a strong man. Our average bows pull seventy-five pounds. Though it is possible for some of us to shoot an eighty-five pound bow, such a weapon is not under proper control for constant use.
Some pieces of yew will make a stronger bow at given dimensions than others. The finer the grain and the greater the specific gravity, the more resilient and active the wood, and stronger the bow.
Taking a yew stave having a dark red color and a layer of white sap wood about a quarter of an inch thick, covered with a thin maroon-colored bark, let us make a bow. Counting the rings in the wood at the upper end of the stave, you will find that they run over forty to the inch.
Ishi insisted that this end of the stave should always be the upper end of the weapon. It seems to me that this extremity having the most compact grain, and the strongest, should constitute the lower limb, because, as we shall see later on, this limb is shorter, bears the greater strain, and is the one that gives down the sooner.
We shall plan to make the bow as strong as is compatible with good shooting, and reduce its strength later to meet our requirements.
Look over the stave and estimate whether it is capable of yielding two bows instead of one. If it be over three inches wide, and straight throughout, then rip it down the center with a saw. Place one stave in a bench vise and carefully clean off the bark with a draw knife. Do not cut the sap wood in this process.
Cut your stave to six feet in length. Sight down it and see how the plane of the back twists. If it is fairly consistent, draw a straight line down the center of the sap wood. This is the back of your bow. Now draw on the back an outline which has a width of an inch and a quarter extending for a distance of a foot above and a foot below the center. Let this outline taper in a gentle curve to the extremities of the bow, where it has a width of three-quarters of an inch. This will serve as a rough working plan and is sufficiently large to insure that you will get a strong weapon.
With the draw knife, and later a jack plane, cut the lateral surfaces down to this outline. The back must stand a tremendous tensile strain and the grain of the wood should not be injured in any way. But you may smooth it off very judiciously with a spoke shave, and later with a file. The transverse contour of this part of the bow remains as it was in the tree, a long flat arc.
Shift the stave in the vise so that the sap wood is downward, and set it so that the average plane of the sap is level. With the raw knife shave the wood very carefully, avoiding cutting too deeply or splitting off fragments, until the bow assumes the thickness of one and one-quarter inches in the center and this decreases as it approaches the tips, where it is half an inch thick.
The shape of a cross-section of the belly of the bow should be a full Roman arch. Many debates have centered on the shape of this part of the weapon. Some contend for a high-crested contour, or Gothic arch, what is termed "stacking a bow"; some have chosen a very flat curve as the best. The former makes for a quick, lively cast and may be desirable in a target implement, but it is liable to fracture; the latter makes a soft, pleasant, durable bow, but one that follows the string. Choose the happy medium.