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An attempt was made to hold the moisture on the string by the use of a hygroscopic agent such as glycerine. But as the moisture content of the glycerine decreased down to the amount which would remain in equilibrium with the atmos-phere the strength of the thread correspondingly decreased. The increase in strength is undoubtedly associated with the swelling of the cellulose fibers. Various swelling agents were tried without any success. There doesn't seem to be much one can do to utilize this very interesting property of linen except to see that the string has at least its equilibrium quota of moisture. For instance, avoid heating the string by vigorous application of wax.

Contrary to common belief, waxing a bowstring does not increase its strength. The following representative tests were made on linen which was treated as indicated and then conditioned at 70 degrees F. and 50% humidity for five days before testing:

Pull Strength
(P) W/f (S.C.)
Thread size 40/3—no treatment 11.1 .0404 54100
Thread size 40/3—waxed under tension by rubbing 11.4 .0515 43600
Thread size 40/ 3—waxed by immersion in melted beeswax—no tension 9.1 .0507 35350
Thread size No. 14—no treatment 85. .369 45400
Thread size No. 14—waxed under tension by rubbing 82. .469 34400

The strength was not appreciably affected when the waxing was done under tension so as to stress the elements of the thread more nearly uniform before the wax hardened thus preventing further adjustment. However the weight was increased thereby lessening the value of the string by about 25%, It seems probable that wax applied under tension at points where wear occurs, as at the nocking point, will increase the life of the string. Wax also helps to hold the serving in place. Fraying of the string can best be avoided by using a tightly twisted thread such as 40/3 button thread. It is difficult if not impossible to construct a reinforced eye splice without using wax; however this use of wax may be avoided by use of the Oriental knot.

Certain it is that the archer who is often seen on the shooting line vigorously waxing his string is generating heat which drives strength giving moisture out of the string; also he is cutting down the cast of his bow by increasing the weight of his string.