Mathematical instruments; time and date stamping machines; time clocks [time recording devices]; safety helmets; laboratory apparatus and instruments; chemistry apparatus and instruments; apparatus and instruments for physics; photographic apparatus and instruments; projection screens for movie films; movie projectors; telescopes; microscopes; measuring apparatus and instruments; rotary converters; electrical cells and batteries; magnetometers; ammeters; voltmeters; wattmeters; conductors, el...

Optical apparatus and instruments, namely microscopes