Lay the braced bow on the floor, place the end of the tiller on the handle while you steady the tiller upright. Then put your foot on the bow next the tiller and draw the string up until it slips in the first notch, say twelve inches from the handle. If the curve of the bow is fairly symmetrical, draw the string a few inches more. If again it describes a perfect arc raise the string still farther. A perfect arc for a bow should be a trifle flat at the center. If, on the other hand, one limb or a part of it does not bend as it should, this must be reduced carefully by shaving it for a space of several inches over the spot and the bow tested again.
Proceeding very cautiously, at the same time not keeping the bow full drawn more than a second or two at a time, you ultimately get the two limbs so that they bend nearly the same and the general distribution of the curve is equal throughout.
As a matter of fact, a great deal of experience is needed here. By marking a correct form on the floor with chalk, a novice may fit his bow to this outline.
The perfect weapon is a trifle stiff at the center and the lower limb a shade stronger than the upper.
The real shooting center, the place where the arrow passes, is actually one and one-quarter inches above the geographic center, and the hand consequently is below this point. Your finished hand grip, being four inches long, will be one and a quarter inches above the center and two and three-quarters below the center. This makes the lower limb comparatively shorter, so it must be relatively stronger. Your bow, therefore, when full drawn should be symmetrical, but when simply braced, the bend of the upper limb is perceptibly greater than the stronger lower limb.
You will find the bow we have made will pull over eighty pounds, even after it is thoroughly broken to the string. It is necessary, therefore, to reduce it further. This is done with a spoke shave, a very small hand plane or a file. Ultimately I use a pocket knife as a scraper, and sandpaper and steelwool to finish it.
Your effort must be to get every part of the wood to do its work, for every inch is under utmost strain, and one part doing more than the rest must ultimately break down, sustain a compression fracture, or, as an archer would say, "chrysal or fret."
"A bow full drawn is seven-eighths broken," said old Thomas Waring, the English bowmaker, and he was right. Draw your bow three inches more than the standard cloth yard of twenty-eight inches and you break it. It is more accurate to say that a full drawn bow is nine-tenths broken.
It is also essential that the bow be stiff in the handle so that it will be rigid in shooting and not jar or kick, which one weak at this point invariably does.
A bow should be light at the tips, say the last eight inches, which is accomplished by rounding the back slightly and reducing the width at this point. This gives an active recoil, or as it is described, "whip ended." This can be overdone, especially in hunting-bows, where a little more solidity and safety are preferable to a brilliant cast.