The Shuckburgh telescope or Shuckburgh equatorial refracting telescope was a 4.1 inches (10.4 cm) diameter aperture telescope on an equatorial mount completed in 1791 for Sir George Shuckburgh (1751–1804) in Warwickshire, England, and built by British instrument maker Jesse Ramsden (1735–1800).[1][2][3][4][5]
It was transferred to the Royal Observatory, Greenwich in 1811 and the London Science Museum in 1929.[2] Even though it has sometimes not been regarded as particularly successful, its design was influential.[3] It was one of the larger achromatic doublet telescopes at the time, and one of the largest to have an equatorial mount.[2] It was also known as the eastern equatorial for its location.[6]
It was pictured in the Rees Cyclopedia of the early 1800s.[7] It was early pictured in Philosophical Transactions, published in 1793.[8]
At the Royal Observatory in Greenwich, it was for a time installed in the North Dome, although this had a Sky view partially obscured by the Octagon room.[9][10] It was earlier installed as an alt-az mount in the South dome at Greenwich, which in 1838 is where the then-new 6.7 inch aperture Sheepshanks refractor was installed.[11]
The telescope tube is 5 feet four inches long (about 1.6 meters).[9] The focal length was the same for this telescope, with object glass being doublet of 4.1 inch (~10.4 cm) aperture.[10][12]
Shuckburgh placed an order with Ramsden for the telescope in 1781, and it was delivered for his observatory ten years later.[13] He also ordered a clock from John Arnold & Son to use with the telescope.[13] The telescope was installed at Shuckburgh Hall, in Warwickshire, United Kingdom.[13]
Observations
The Shuckburgh/ Eastern telescope was used for the 1832 transit of Mercury equipped with a micrometer by Dollond.[14] By observing the transit in combination with timing it and taking measures, a diameter for the planet was taken. They also reported the peculiar effects that they compared to pressing a coin into the Sun. The observer remarked:
I afterwards observed, that immediately around the planet there was a dusky tinge, making it appear as if, in a small degree sunk below the sun's surface;[14]
The Shuckburgh and the western equatorial at Greenwich are recorded as having been used for observations of the 1835 apparition of Halley's Comet.[15]
The Shuckburgh, also called the "Eastern Equatorial" at the time Halley's comet was sometimes used with a micrometer microscope.[6] For the observations of Halley's 1835, the Transit and Arnold 1 and 2 clocks were used.[6] Observations were recorded in August, September, and October, but it could not view the comet after October 19, because its view was blocked by another part of the observatory building.[6]
The Shuckburgh is also reported to have been used for observing the occultation of stars by the Moon and observing the moons of Jupiter.[16]
