The second question of interest is the effect of "creep" on accuracy. Suppose the archer holds his anchor and his aim correctly, but permits slight relaxation of his left arm, or allows his anchor to shift slightly, resulting in "creep". Where will the arrow strike the target?
Again we must establish definite conditions. If we assume a velocity of 150 feet per second, when the bow is fully drawn, we must first find the effect on velocity of a creep of given amounts, say ½ inch. Dr. Hickman has found that velocity is, within limits, proportional to the draw, measured from the braced string. This enables us to determine the reduced velocity resulting from creep. If the bracing height is 7 inches, and the arrow is 28 inches, the full draw is 21 inches, and the reduced draw 20.5 inches. We find that the reduced velocity is 20.5/21 of 150 or 146.5 feet per second. With the same initial angle in both cases, where will the arrow strike, at the reduced velocity, if it hits the center of the gold at 150 feet per second? Table III gives the results for the different distances:
TABLE III | ||
Target Distance, | Hit, inches below target center | |
yards | Creep, ½ inch | Creep, ¾ inch |
40 | 5.9 red, inner | 8.8 red, outer |
50 | 9.4 red, outer | 13.8 blue, outer |
60 | 13.5 blue, middle | 20.0 white, inner |
80 | 24.5 petticoat | 36.8 miss by a foot |
This table confirms what every archer knows—that creeping is a disease fatal to good scores. Of course this applies only to variable or occasional creeping. If the creep is exactly the same each time, allowance will be made for it in the point-of-aim or the setting of the sight. Nevertheless, it is far better not to creep, since its presence introduces into the technique of shooting another factor which, as one gets tired or physically below par, is bound to become variable and give trouble.
My own general conclusion regarding errors in aiming, as related to the question of point-of-aim versus sight, is that we are dealing with "six of one and a half dozen of the other", so far as the mechanical principles of aiming are concerned. But archery is so bound up in psychology that some will swear by the point-of-aim and at the sight, and others vice versa. In my case, and the cases of others who shoot with me, the sight has been of unquestioned benefit, and its advantages as enumerated in the January issue of Ye Sylvan Archer are proving with continuing experiences to be very real.