Graph 7 A shows the effect of bow length on the drawing force and string tension. Curves are given for bows having lengths of 4, 5 and 6 feet. The weights of the bows are the same for a draw of 27.5 inches. These curves show that the work that may be gotten out of a bow goes up with the length. The string tension also goes up with bow length. The long bow will give a heavy arrow higher velocity, however, due to dynamical considerations that will be treated later, the short bow may give a light arrow a higher velocity than can be ob-tained from a long bow.
Graph 7B shows the effect on fiber stress of bow length. For a given force at full draw, the short bow has the greatest fiber stress. This same graph shows the limb thickness required to give the same full-draw force for different length bows. The longer the bow, the greater the thickness required.