Physics – Optics
Scientific paper
Jan 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011aas...21714606b&link_type=abstract
American Astronomical Society, AAS Meeting #217, #146.06; Bulletin of the American Astronomical Society, Vol. 43, 2011
Physics
Optics
Scientific paper
Before addressing queries about how and what to preserve among astronomical devices, the question of what constitutes a historic instrument must be considered. Certainly, the lenses are the defining feature of a Clark refractor. Since 1867, when Newcomb inquired about the possibility of obtaining a great glass from Alvan Clark & Sons, the U.S. Naval Observatory 26-in (66-cm) equatorial has evolved in response to improvements in technology and changes in its observing program. After two major overhauls, only the objective remains of the equipment originally installed by the Clarks in 1873 at the old Observatory site in Foggy Bottom. However, the telescope retains its reputation as a historic Clark refractor.
The USNO telescope was briefly renowned as the largest refractor in the world; the second of five such achievements by the Clarks. Through it, Hall first detected the moons of Mars in 1877. However, by that time, the Clarks had already refigured the flint glass. Hall and Gardiner had also altered the drive mechanism.
When the USNO moved to its present Georgetown Heights location in 1893, the great equatorial was refurbished with its original Clark optics installed on a more robust Warner & Swasey mount. Peters eventually incorporated discarded parts from the original mounting into his photographic telescopes during the first half of the 20th century. The 26'' refractor underwent further modernization in the early 1960s to facilitate the xy-slide of a Hertzsprung-style photographic double star camera. In 1965, the objective was disassembled for cleaning and reassembled with new spacers. The most recent maintenance included re-wiring and replacing several motors and the hand paddles.
Originally designed as a visual instrument, the USNO 26'' Clark refractor now hosts a speckle interferometer for its current double star program. Despite continuing modifications, this telescope remains a fine example of the optician's art.
Bartlett Jennifer L.
Hartkopf William I.
Mason Brian D.
No associations
LandOfFree
The USNO 26'' Clark Refractor; From Visual Observations to Speckle Interferometry does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The USNO 26'' Clark Refractor; From Visual Observations to Speckle Interferometry, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The USNO 26'' Clark Refractor; From Visual Observations to Speckle Interferometry will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1394925