Some fletchers glue the feathers straight on the shaft whileothers put them on with a slight spiral. No one has everproved that one system is better than the other. Naturally, thespiraling of feathers is for the purpose of causing the arrowto rotate in flight thus holding it on a more steady course. Asa matter of fact, feathers have a natural curve that has the sameeffect as spiraling but to a lesser degree. If we apply themathematical formula used in rifling firearms, we find that
the "twist" would be exceedingly slow for an arrow. Thenatural curve of the feather gives a faster rotation than theabove formula calls for.
