Comparison of the Mechanical Stages the Nelson No 1a(left) vs the Powell & Lealand No 1(right)

This page is devoted to a comparison of the stages of the late model Powell & Lealand No 1, and the Curties-Nelson-Baker No 1a.

Note that both these stages had the same basic layout and features including a calibrated stage rotation on a thick round metal plate. In both cases there is a double calibration ring, the outer calibrations graduated in single degrees and labelled every ten, while the inner is graduated in half degrees.

Note that both had very flexible adjustments for slide width, Turrell-type stages, and calibrated stage rotation. In both cases, the front slide rest has spring-loaded contact with the slide.

This image illustrates the similar mechanism for stage rotation of the Nelson-Curties No 1(left) and the Powell & Lealand No 1(right). In both cases, the bevel gear is permanently engaged, but the mechanisms allow manual stage rotation as desired. It also shows virtually identical cam-and-follower mechanisms for X-axis movement and rack and pinion movements for Y-axis movement.