Lantern slide of the photoelectric photometer around 1925. From the Observatory's lantern slide collection, marked "PE 2." Robert Baker continued Stebbin's photometry work when he arrived at Illinois in 1923. He continued to use the 12-inch…
Lantern slide of the 30-inch reflecting telescope after it was rebuilt between 1925-1927. The dual-channel photoelectric photometer hangs on the end of the telescope. The rebuilt telescope was located in a 15-foot domed Observatory located on…
The photocell is hand blown glass or quartz. Within in the cell is an alkali metal (lithium, sodium, or potassium) that covers the inside and is a cathode emitting electrons when illuminated. A well insulated wire forming a ring centered in the…
Wooden frame with moveable seat and eight steps on four castors. Measures 45” x 48” x 103” tall. Moving adjustable chair with foot-rest connected to counter weights slides up and down in the middle of the stairs with in a wooden track.…
Also Foucault siderostat. Marked “Societe Genevoise, pour la construction, D’instruments de physcique, Geneve.” Wind up drive does not work. Spirit level on black metal base with 3 leveling screws.
Two examples of approximately 270 photographic plates and films taken with the 12-inch refractor and the plate camera. Most of the photographs date to the late 1950s and early 1960s.
Figure 2: Galvanometer and accessories for the selenium photometer. Page 191.
Visible in the photograph are the galvanometer, reading telescope, scale, batteries,Wheatstone bridge, and resistance boxes. Was located in the west-central transit…
Wooden box (dimensions) with hinged lid, with 4 colored shades (2 green, 2 red), 3 eyepieces with adapter, one smaller eyepiece with adapter, accessories for light.
“Its filar position micrometer consists essentially of a…