ANOTHER WAR INSTRUMENT.

Thames Star, Volume VII, Issue 2644, 29 June 1877, Page 3

ANOTHER WAR INSTRUMENT.

I had another opportunity the other day of examining General Berdan's new dis-tance-calculator, or in military language, 11 range-finder," which is making such a sensation here in military circles. When closed up, ready for moving, it looks like a sort of primitive chariot, mounted on two large light wheels and drawn by one horse. Two men ride upon the comfortable seat, the driver and the operator, and for the latter, so simple is the instrument, no special training is necessary, however desirable it may be that, he should understand the principles of trigonometrical science. When the range of any point is taken, before a bßttery begins ft> play, for instance, or a regiment to fire, the horse is slipped out of the shafts and the body of the " chariot" then turned completely over on itte axle. The frame, on which is built the seat, then serves as a firm and steady support for the instrument. The body of the vehicle is a box or case one meter wide, nearly two long, and about a foot deep; an 3 when its two opposite ends are thrown open, the instrument is ready for use. Thjs consists, loosely described, of two parallel telescopes about one and a half metres long, and very powerful, affixed to a frasp|.which swings on a common pivot. The sigut ends are just one metre apart, and this is, of course, the base line'of calculation. One of these telescopes is movabj^only with the frame, of which both form a part. This is first sighted on the object, and then the frame is made fast, the first step being thus completed. The other telescope is adjustable further, on a pivot of its own, and by means of a small wheel is turned 'to the right angle of convergence with its companion—that is to say, until it too covers the object. Now, having the base line and the angle of convergence, any surveyor could, of course, calculate the distance. But in Gen. Berdan's instrument, the wheel which adjusts the second telescope is marked off into meters, centimenters, and milimeters, and is covered by a little hand or pointer, and when the hand is brought within the focus the pointer indicates exactly the distance. This is absolutely all there is of it. Jn two minutes the in-" gtrument pan be unlimbered, put into readiness, and a distance found.—Berlin Correspondence London Daily News.