A Surveying Camera

A surveying camera, styled the Bridges-Lee instrument, is being introduced in England. It resembles an ordinary camera, having a brasa bound box with rapid rectilinear lens aud doublé backs, and the usual ground glass sereen. The camera body taina on a horizontal plafce having a graduated rim, over which slides a vernier attached to the camera for reading horizontal angles. A clampiug acrew fixes the camera body to the bottom plate, which plate is monnted on a tripod head provided ■with leveling screws. On top of the camera box is fixed a rotating level and telescope mounted on a horizontal arm and fitted with a rack adjustment and scale, permitting vertical angles to be taken. This telescope has a vertical wire, which bisects the picture on the ground glass screen, and as coplanary with a second vertical vire inside the camera. This wire casts a shadow, Vfhioh is clearly diseernible on the sensitive plate or filrn when developed, and thns marks the center line of the picture. Behind this wire is a compass, mounted on a rack iuside the camera, by rneaus of which, when a photograph is to be taken, it can be moved back nntil it just fails to touch the plate. The graduation of the compass card is carried out on a vertical strip of translucent material, through which the iight passes to the plate, thus photographing thereon the compass bearing. A horizontal fiber is also placed inside the body of the camera, similar to the vertical one, which, when the instrument has been properly leveled,