Signedunsigned
Inscribedin black crayon on box: 10" Rear / Combination / Boyden Doublet
in black paint on box lid to right of handle: 26 / I
in black paint on box side: No. 25.
in pencil on inner edge of box below lid: Focus: 38' (2")?
Historical AttributesThis is a 10-inch doublet lens was the rear-end combination of a pair of doublet lenses that made up a photographic refractor paid for by the Boyden Fund. The Boyden Fund was given to Harvard College Observatory in 1887. This instrument was made about 1889 by Alvan Clark & Sons.
In the nomenclature of the Harvard College Observatory, the 10-inch photographic telescope was known as the "10-inch Boyden Doublet" because it had two lenses. (In modern nomenclature, we might say that the photographic telescope--aka astrograph--had a camera lens consisting of two doublet lenses.)
The 10-inch Boyden photographic telescope was likely one of the HCO instruments used in the high-altitude observatory in Arequipa, Peru, which was called the Boyden Station. It was used for photography of stars and the like.
After work in the field, the instrument was stored at the Agassiz Station. It was retrieved from there on May 21, 1969.
ProvenanceHarvard College Observatory, purchased circa 1889; gift to CHSI in 1969.
Published ReferencesDeborah Jean Warner and Robert B. Ariail, "Alvan Clark & Sons: Artists in Optics, 2nd ed. (Richmond: Willmann-Bell, 1995), 108, 206.
Bessie Zaban Jones and Lyle Gifford Boyd, The Harvard College Observatory (Cambridge: Belknap Press, 1971).