1851 Great Exhibition: Official Catalogue: Class VIII.: David Davidson
238 DAVIDSON, DAVID, Captain, Bombay Army, per C. H. DAVIDSON, Haddington — Inventor. Manufactured by J. ROBERTSON, Haddington.
Double and single barrelled rifles; double and single 10-inch rifled pistols; single 6-inch pistol; all with telescopic sights. These rifles are furnished with grooved bullets.
The telescopic sight can be fixed to the piece in a moment; it in no way interferes with the usual sights. In the use of the common sight the unassisted eye cannot observe with distinctness, at the same instant of time, two or more objects at different distances from it; and as the breech sight, the muzzle sight, and the object aimed at, are necessarily at different distances from the eye, it is difficult to bring them at once into line, and at the same time to give the proper elevation to the piece. This disadvantage is obviated by the use of the telescope, since the lines placed in the focus of the eye-piece, and the object aimed at, as seen through the glass, appear equally distinct to the eye.
The grooved bullet sustains the spinning motion, so that the pointed end goes foremost throughout the longest flight. The groove in the zone reduces the friction, gives the rifling a firmer hold so as to prevent stripping, and secures its longer axis continuing in the axis of the piece. It is less affected by wind, and has greater power of penetration than the round bullet.
The telescopic sight also enables the sportsman to estimate the distance of the deer.