HYPOSCOPE (from Greek words mean ing uto see under"), is the name given to an instrument adapted to be secured to the stock of a rifle near the breech, and intended to enable a marksman to fire with accurate aim without exposing his head to the fire of the enemy. The successful American contestants for the Palma trophy at Bisley, England, in 1903, brought back with them this device, which seems likely to play an important part in the warfare of the future: It was invented by Wil liam Youlton of Brighton, England, who con ceived the idea of it after the battle of Colenso in the Boer War, during which it is stated that not a single Boer was to be seen. Later in the war it was employed with good results, its use at Mafeking receiving particular mention.
The hyposcope consists of a series of mir rors mounted in a tube of inverted L shape; the shorter arm lies across the barrel of the rifle, while the longer arm hangs down at one side.
The first mirror reflects the light coming in along the barrel of the rifle to a second mirror at the elbow of the instrument, which directs the rays downward to a mirror at the lower end of the tube, and thence it passes out at right angles to the eye. Thus on looking in at the eyepiece one can see the sights of his rifle, and take accurate aim while holding the gun above his head. The vertical arm of the instrument comprises two telescoping sections so that, by means of a thumbscrew at the side, this arm may be extended to elevate the device for long range shooting. The amount of elevation may
be accurately determined by means of a fine scale on the upper section. In order to allow for windage, a thumbscrew at the end of the horizontal arm may be rotated to move the mirror contained therein slightly to one side or the other. A scale on this arm shows just how far the mirror must be moved for different velocities and directions of the wind. The entire instrument is very compact and light, weighing about a pound. It is provided with a holster in which it may be encased to prevent it from sus taming any injury when not in use.
The advantages of this instrument in actual warfare will be apparent to all. Only the muz zles of the rifles are exposed to the enemy, and the soldiers are entirely concealed in the trenches. But aside from its advantages as a means of protection, the device will be found greatly to increase the effectiveness of the firing. The fear of being shot while taking aim makes the soldier fire hurriedly and at random; with the hyposcope attached to his rifle no fears will be entertained, and the soldier may fire de liberately and withperfect aim. By applying it to the end of a field-glass, an observer can watch the movements of the enemy without dan ger of discovery. It has also been designed for use on Maxim guns. Hyposcopes and similar instruments were much used by snipers during the great World War.