Searls Surface Tension Apparatus
The bridge has raised end pieces to which are screwed small metal blocks securing either end of a plated steel torsion wire. One block disc slotted to facilitate adjustment for torsion of the wire by means of screw passing through the end piece. At the centre of the wire, a small clamp is fitted carrying a light weight metal pointer with an adjustable counterpoise. From a notch near the tip of the pointer is suspended a small weight pan with a hook fitted to its underside, to hold either wire frame or a metal clip carrying a glass microscope slide. The tip of the pointer moves over a graduated vertical scale complete with set of weights.