Time Star to measure the constants of elliptical polarization and double retraction due to strain in transparent media.

The compensator consists of two wedges of quarts, one fixed with optic axis in one direction while the other moving with optic axis in a perpendicular direction. The movable wedge is moved by means of a micrometer screw with a readable accuracy of .005mm. The total movement of the same is 20 mm. The wedge system fixed in a box which is an integral part, can be rotated in a circular scale with nleast count 1/10 degree, fine and course movements are provided. The analyzer has an independent scale which can be arranged in any angular position with respect to wedge. The fringe width is 6 mm. Completed in cabinet.