Bausch & Lomb Optical Company the same angle to the mirror, M', which stands parallel to M and reflects the beam in a direction parallel to the axis of the projection apparatus. … The mirror, M', is made of black glass and covered with two plane glass plates The light becomes polarized by reflection from this mirror and passes through a pair of quarter-wave mica plates, P, one of which may be rotated so as to rotate the plane of polarization. It is then converged by the…
