Experimental Data on Bow Wood
These were set in a vise so that 12 inches projected. To these ends a spring scale was successively attached and the wood drawn a distance of 4 inches from the perpendicular.
No. 2 registered 11 pounds.
No. 3 registered 14 pounds.
The fine-grained red yew is evidently strongest. The breaking point of each was tested. Number 1 was drawn 12 inches from the straight line without fracture. In fact, it was capable of bending at right angles, without breaking. Number 2 broke at 6 inches. Number 3, when drawn 5 inches, fractured. The white sapwood is thus shown to be more elastic than brittle. The red wood is brash and strong.
To test the shooting qualities of the white and red yew, two miniature bows were constructed, each 22 inches long and of the same diameters throughout.
No. 2, red yew from the same log. When drawn 8 inches, it pulled 10 pounds.
Shooting a 10-inch arrow, weight ⅙ of an ounce, drawing each shot only 8 inches:
No. 2 shot a maximum flight of 63 yards.
To test them, under conditions of equal weight, number 2 was reduced by shaving its limbs until it pulled 8 pounds, its outer limbs being given a quicker cast thereby. Shooting the same arrow, it now made a maximum cast of 66 yards, demonstrating the superior casting quality of the red wood over the white when drawing the same weight.
Mr. Will Thompson, the well-known American archer, at one time had a bow constructed of several lamina of white sapwood glued together. He hoped by this means to obtain a bow of unusual cast. It is reported to me by
W. J. Compton, who saw and shot this bow in the workshop of Barnes, the Oregon bow maker, that it was a complete failure as a bow and had a dull, weak cast.
To test the influence of backing on the shooting quality of a bow, the small miniature of red yew was heavily backed with catgut strands and very thin rawhide, set with glue. Before backing, the bow pulled 8 pounds and shot 66 yards. After backing, the bow pulled 10 pounds and shot 63 yards. It therefore appears that the backing does not add to the cast of a bow but probably only prevents it from being broken when overdrawn. As a test, an arrow was drawn 10 inches on it and under these circumstances it shot 85 yards. When drawn 12 inches it fractured straight across the handle.