Browse Items (3473 total)

Hand sized brass spectroscope with small button to shut aperture. For looking through to see spectrum of sky, mainly to judge water absorption levels

13 masks in individual envelopes in a clear plastic box. Masks are square pieces of glass painted black with either a pin hole window or a circular band.

Hand blown wide oval glass jar. Base rim is added glass ring

glass dome with brass neck piece and large brass knob

a glass apparatus dome cover with green velvet covered rim

one of a pair, circular base weighted with lead, the vertical tapers upward from a bulbous bottom, terminating with a wing nut for holding a telescopic inner section of glass rod

glass specific gravity hydrometer, red lead weighted, scale 1200 to 1300. In cardboard tube

Used carbon filament lamp (16 cp?) with standard bayonet cap. Marked "BTH Edison". Conspicuous darkening of inside of bulb

four rods for stroking with fur to produce electrostatic charge. Materials differ and are probably not amber (Gr electrum). Wrapped in grey woven material

box, wooden frame with glass front and back. Brass rod connects a gold leaf to a top touch disc. Copper leaf against one side connected to an external thumb nut contact. Silver foil lining.