Wind-gauge

In a military sense, is an attachment to the sight (either front or rear-sight) of a fire-arm by which an allowance for the effect of wind on the projectile can be made in aiming. Though usually called wind-gauge , it is also used to counteract drift or any other deviation which can be anticipated. In the old model target-rifles, the front-sight is capable of a slight movement. Some of the more recent military arms have a wind-gauge attached to the rear-sight. In the peep-sights , the sight-piece is moved by a screw. In the present U. S. service rifle the sight-piece is moved by hand. It has graduations to guide the marksman. The wind-gauge is frequently attached to breech-sights of cannon in Europe. In this country the Parrott gun is similarly equipped.