'Bactil' Binocular Microscope in Case, by W. Watson & Sons, London, ?c.1960

The Y-shaped foot and short pillar carry the curved limb on trunnions. A locking lever on the stand holds the inclination of the limb. The optical components are mounted on a housing that moves on the limb on a rack and pinion for coarse focusing. A mill-headed screw on the housing operates the fine focus. Four objectives are held in a rotating changer. The eyepieces push into tubes in the binocular head. The inter-ocular distance is adjusted by a milled screw on the head and the right hand eyepiece 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, aligned and is fitted with an iris diaphragm. The Plano-concave mirror is set on a post on the lower end of the limb. The instrument has a wooden carrying case which can be locked closed.