The base of the solar microscope has controls for mirror tilt (A), mirror rotation (B), and two thumbscrews (C) for attaching the microscope to a frame. 15.5x15.5cm.
The rectangular mirror reflects sunlight into the microscope body. Mirror = 17.5x5cm
The mirror is tilted via this worm drive (arrow).
The worm gear is held in place by this steel pin.