This included the erection of the Observatory's fairly unique telescope, the 10-inch Siderostat-type Refractor Telescope produced by Chicago's Gaertner Scientific Company. Unlike most telescopes, the Siderostat-type telescope is mounted horizontally on a concrete base and does not move. A moving mirror, behind the telescope, reflects the Sun, Moon, planets, and stars into the telescope. This telescope continues to be the second largest operable, Siderostat-type telescope in the world!
Well-known Astronomer Harlow Shapley, who was then Director of the Harvard College Observatory, presented the keynote address at the dedication ceremony. First Light, through the Siderostat-type telescope, came from the ringed-planet Saturn.
The Buhl Planetarium and Institute of Popular Science had actually been dedicated and conveyed to the City of Pittsburgh, by the Buhl Foundation(at that time, thirteenth largest foundation in the country!), on October 24, 1939. Prior to the Observatory dedication ceremony, Buhl's third floor observatory had been used by the Amateur Astronomers' Association of Pittsburgh(AAAP) for public observing with portable telescopes. Once the Siderostat was in use, AAAP members supervised public observing sessions on clear evenings--at that time, Buhl was open to the public every evening(except New Year's Day) until 10:30 p.m.!
Along with the acquisition of Buhl's Zeiss II Planetarium Projector(now the oldest operable, major planetarium projector in the world!), the Buhl Planetarium also ordered a portable telescope from the Carl Zeiss Optical Works in Jena, Germany in 1939, for use in the Observatory. To the dismay of Buhl officials when opening the package from Germany, they received a 4-inch terrestrial refracting telescope(which uses additional optics to show a right-side-up image); they had ordered an astronomical refractor telescope(which has fewer lenses to degrade the image and shows an upside-down image).
However, with the commencement of World War II on September 1, 1939, they could not return the telescope to Germany and have an astronomical refractor sent in its place. Hence, they had to make-do with a terrestrial refractor. So, today the City of Pittsburgh owns a good Zeiss telescope(now used at the Henry Buhl, Jr. Planetarium and Observatory of The Carnegie Science Center) with a very interesting history!
In addition to evening use, the Siderostat projects a superb display of the Sun onto a large projection screen, showing both sunspots and granulation on the solar surface. Also, during daytime hours, the public has been able to view the planets Mercury, Venus(showing phase), Mars, and Jupiter(including cloud belts), as well as the Moon and stars down to third magnitude, with the Siderostat.
Although primarily used for public observing, the Siderostat has been used for some research, from time-to-time. During the 1980s, Buhl Planetarium Lecturer Francis G. Graham(Founder of the American Lunar Society) took photographs of the South Pole area of the Moon, as part of a cooperative research project with other American astronomers. These photographs aided the production of a better map of the South Pole area of the Moon, than existed at that time.
Dedicated as "The People's Observatory" in 1941, this name fell out of use after World War II. During the Cold War, the proliferation of Communist states known as "People's Republics" tarnished the meaning of the word "People's." Hence, "The People's Observatory" name was no longer used--which is a shame considering that Buhl Planetarium used the word "People's" first!
Another interesting historic anecdote: On the same evening of the Observatory dedication, Buhl started a new Planetarium Sky Show and opened a new gallery exhibit. The Sky Show, regarding Celestial Navigation, was titled "Bombers by Starlight"(Buhl provided Celestial Navigation classes to many military servicemen, during World War II). The new exhibit, in Buhl's lower-level Octagon Gallery(which encircles the planetarium projector pit, below the planetarium's "Theater of the Stars") was titled "Can America Be Bombed?" This exhibit opened two and one-half weeks before the Japanese bombed Pearl Harbor, Hawaii!
Although Buhl Planetarium's People's Observatory has not been used since 1994, it is hoped that it may be reopened to the public within the next few years.
More information on the history of The People's Observatory at Buhl Planetarium can be learned on the Internet at the following address: