Details
An early light bulb,
with special coil filament, with indistinct registered trademark; a Stanley-Boucher calculator -- 2in. (5.1cm.) dia.; and a prismatic sighting instrument with trademark for OML Slough England -- 10in. (25.4cm.) long (3)
with special coil filament, with indistinct registered trademark; a Stanley-Boucher calculator -- 2in. (5.1cm.) dia.; and a prismatic sighting instrument with trademark for OML Slough England -- 10in. (25.4cm.) long (3)