The appearance of the comet known as "Donati's Comet", discovered in Florence by Giovanni Donati on June 2, 1858, gave the initial stimulus to the founding of the observatory. Interest in the comets appearance caused a group of men (professional and business) to form the Allegheny Telescope Association. This group, among whom the most prominent were Professor Louis Bradley, Josiah King and Harvey Childs, met in Bradley's home on February 15, 1858, and resolved not only to found the A.T.A. but also to purchase a telescope. On January 31, 1860, the A.T.A. ordered a 13-inch telescope from Henry Fitz of New York, and it was installed in 1861. On May 15, 1860, the A.T.A. officially adopted a constitution and by-laws, elected a board of directors, and appointed an Observatory Committee. This committee raised funds by subscription for the telescope and housed it in a new building which they called the "Allegheny Observatory" as it was centered on a hill on Perrysville Avenue in the old city of Allegheny. Professor Bradley was custodian of the new telescope from 1861-1863. In 1865, Professor Philotus Dean, principal of Central High School in Pittsburgh, became first custodian of the Observatory. Both men served without pay, accepting the responsibility of the Observatory to promote the advance of science. Later in 1865, the A.T.A. deeded the telescope, the building and the land to the Western University of Pennsylvania (now University of Pittsburgh). In 1867, the official transfer was completed and Samuel Langley was appointed Director. Among many other accomplishments, Langley invented a device to measure the temperatures on the Sun's surface, known as a bolometer; "Standardized" time for railroad companies; and coined the terms "astrophysics" and "aerodynamics" . When Langley left to become Secretary of the Smithsonian in 1887, James Keeler became the acting director and used the 13" Fitz-Clark telescope to discover Saturn's rings were made of small particles instead of being one large disk. In the early 1890s, because of the increasing air pollution in Pittsburgh and the need for larger research facilities, a new building at a new site was designed. The new Allegheny observatory was built between 1900 and 1914 in Riverview Park. The old observatory was sold and at one point a hospital for an orphanage. The building was torn down in 1955. The Fitz-Clark 13" is still used today. In 1974 a bequest in the memory of George Theiss was made to the Observatory allowing for renovations on the Thaw and Keeler Telescopes. The George W. Theiss Astronomical Laboratory was also established and houses machines used to measure stellar images obtained from telescopes. The Thaw lens was replaced in 1985.
From the description of Allegheny Observatory records, 1850-1967. (University of Pittsburgh). WorldCat record id: 30052829
