Searle's Pattern. Spirit level mounted in two rectangular cast iron frame with one end resting on point of micrometer screw, fitted in one frame, the second end of spirit level pivoted in the second frame. The micrometer is provided with vertical scale 10 mm. on either sides of the zero and vernier reading 0.01 mm. Complete with ceiling bracket having two self-centering chucks and tension weight. Supplied in case.