26 [ PHOTOGRAPHIC CAMERAS; ] OPTICAL INSTRUMENTS-NAMELY, [ OPTICAL GAUGING INSTRUMENTS, OPTOMETERS, ] ALIGNMENT TELESCOPES, AUTOCOLLIMATORS, [ PROFILE PROJECTORS ] AND LENSES [ ; AND PRECISION MEASURING INSTRUMENTS-NAMELY, LINEAR DIMENSION GAUGES, SURFACE ROUGHNESS GAUGES AND PEN RECORDERS ADAPTED FOR USE WITH SCIENTIFIC INSTRUMENTS FOR RECORDING PURPOSES ]