Signedunsigned
Inscribedground edge marked faintly in ink: Front Lens
ground edge marked in pencil: OUTER EDGE [in a box] or NEXT MIRROR [followed by an arrow pointing down]
FunctionLunar observing and photography.
Historical AttributesIn November 1899, Edward C. Pickering, director of the Harvard College Observatory, asked Alvan Clark & Sons to grind and polish a pair of 12-inch glass disks to make a lens with a focal length "as nearly as may be 135 ft. 4.1 in." He asked them to "please use Clark curves." The cost would be $900 plus $50 for the cell.
A gift to the Harvard College Observatory in 1900 made the project possible. Pickering had wanted to procure this telescope to try to photograph stars with it. His brother, William H. Pickering, was assigned to test it . Using money from the Boyden Fund, William went to Jamaica and set up the telescope on the grounds of a rented house in Mandeville.
The 135-foot telescope performed rather poorly as a photographic instrument for stars fainter than 7th magnitude, but it was excellent in photographing the moon.
William Pickering became convinced that the moon had canals and snow caps like Mars was thought to have at the time. He spent more than a year in Jamaica observing, drawing, and photographing the moon with the 135-foot telescope. He returned to Cambridge in 1903 and published the first complete "Photographic Atlas of the Moon." The atlas had 80 photographs.
Eventually, the 135-foot telescope was returned to the Harvard College Observatory and put in storage at its Agassiz Station in Harvard, Massachusetts. This objective lens was retrieved from Agassiz Station on 20 May 1969.
ProvenanceHarvard College Observatory, at the temporary and permanent observing stations in Mandeville, Jamaica; return to Agassiz Station; transfer to CHSI, 1969.
Published ReferencesDeborah Jean Warner and Robert B. Ariail, "Alvan Clark & Sons: Artists in Optics, 2nd ed. (Richmond: Willmann-Bell, 1995), 108.
Bessie Zaban Jones and Lyle Gifford Boyd, The Harvard College Observatory (Cambridge: Belknap Press, 1971), 370-371.