M25 Series Binocular Microscope in Case, by Cooke, Troughton and Simms, York, Mid 1950s

M25 Series binocular microscope, manufactured by Cooke, Troughton and Simms. The instrument is painted black and stands on a base that can hold an electric illuminator or, in this case, a mount for a Plano-concave mirror. A housing standing on the base carries the stage, condenser and curved limb. The housing holds the mechanism for fine focusing and the limb moves on a rack and pinion for coarse focusing. These are adjusted by concentric controls on each side. The binocular head is set on a swivelling mount at the end of the limb. A rotating disc of optics is incorporated into the mount. A rotating objective changer holding four objectives is mounted below the limb. Eyepieces drop into tubes in the head, which slide to adjust the inter-ocular distance. Both eyepieces can be focused independently. The stage is mechanical, moved by rack and pinions. Two Vernier scales show the degree of movement in each direction. Specimens are held on the stage plate between two sliding brackets. The sub stage condenser can be focused, is fitted with an iris diaphragm and a rotating disc of phase rings to match the objectives. Four screws on the assembly allow the alignment of the components to be adjusted.

The instrument is provided with a wooden carrying case and dustcover.