Abstract: A power driven micrometer for engaging a workpiece surface has a rotatable screw and a motor for rotatingly driving the screw. The screw and motor are secured together for longitudinal travel as a unit, the screw being threadedly engaged and supported by a nut in the micrometer casing. A key precludes rotation of the motor relative to the casing while enabling longitudinal travel of the motor relative to the casing.

Abstract: An optical mount enabling independent orthogonal adjustment of the angular position of an optical element comprises a cell adapted to receive an optical element and a base defining a chamber open on one side thereof for receipt of at least a part of the cell therein. The cell comprises a circumferentially extending partial spherical section and a pair of portions extending outwardly of the spherical section, and the base comprises an angular seat on the open side receiving and conforming to at least a portion of the spherical section of the cell and a pair of portions extending outwardly of the seat and facing the cell portions. A pair of independent adjustable means spaced from each other by substantially 90.degree. are secured to one of the portion pairs for movement therewith and have parts adapted to operatively abut against aligned sections of the other of the portion pairs. The parts of the adjustable means and the corresponding aligned sections of the other portion pair are biased towards each other.