Telescope: Cooke 6-inch Equatorial No.2

All six of the six 6-inch Equatorials originally assembled for the British 1874 Transit of Venus expeditions were formally transferred to the Royal Observatory between 2 June 1877 and 16 May 1878 (ADM190/4/401–404).

Various new instruments, including two 6-inch Equatorials by Cooke (Cooke No.1 and Cooke No.2) were ordered in 1881 for the British 1882 Transit of Venus expeditions (RGO6/283). In addition, various other instruments were borrowed including from the Royal Observatory. Amongst these was the Naylor 6-inch Equatorial.

Following the loss of the Naylor at sea on its return journey, Cooke No.2, which was sent to Brisbane and returned in 5 cases (RGO6/283/461) was transferred to the Royal Observatory as a replacement (RGO6/283). It was transferred to the  National Maritime Museum in 1998 when the Observatory was closed down (Object ID: ZBA0757).


Post Transit of Venus history

Following its arrival at the Observatory the telescope has spent most of its life in packing cases. A summary of its subsequent history is given below:

1887, June: Mounted in South Ground (BofV Report)

1889: Dismounted (BofV Report)

1929: Loaned to Radcliffe Observatory for use in South Africa 30 December 1929 (see correspondence in E5) (RGO39/5/88).

1930: Returned from South Africa except O.G. 29 July 1930. O.G. returned by Dr Steavenson 9 September 1930. From inventory (RGO39/5/88).

1965: Installed in Dome C at Herstmonceux in December following renovation (Wilkins part 1 p.127)

1973: Removed from Dome C to make way for the Steavenson 30-inch reflector from the Cape Observatory

1998: Transferred to National Maritime Museum


Details of detached parts

The 1893 Inventory (RGO39/10/78) lists the following parts

On the ground floor of the south wing of the New Physical Building

Cooke 6-inch Equatorial Telescope Finder and Driving Clock

In the Museum (central octagon) of the New Physical Building

1 Object Glass
1 Adapters, straight
1 Adaptor, diagonal (in two parts)
5 Eyepieces, negative
1 Eyepiece, low power, (30) with adaptor
5 Dark shades
1 set metal guards
1 Metal guard
1 Striding level
1 Bifilar micrometer, with 4 eyepieces and 3 dark shades

A second set of entries in a partial inventory made in 1895 states that the items are as in the inventory above, but differs slightly in both detail and the inclusion of a Double image micrometer. The full list of items is as follows:

1 Object Glass
1 Bifiliar micrometer in box with 4 eyepieces and 3 dark shades
1 Double image micrometer with divided lens - 2 eyepieces
1 Striding level
1 Empty tool box
Box of eyepieces containing:
   1 Eyepiece, low power, (30)
   5 Eyepieces 120, 140, 200, 300, 450
   2 Adaptors
   1 Adaptor, diagonal
   5 Dark shades
   1 set guards

List of telescopes installed at different times in Dome C at Herstmonceux

When the telescope domes of the Equatorial Group at Herstmonceux were built, it had been planned to erect a new Schmidt Telescope in Dome C. Money for this was not forthcoming and the dome was subsequently used as follows:

1956-1961: The Isaac Roberts 20-inch reflector on loan from the Science Museum. Dismounted by July

1965-1973?: Cooke 6-inch equatorial No.2. Installed December following renovation (Wilkins part 1 p.127) Purpose unknown

1973-1980 Steavenson 30-inch reflector from the Cape Observatory

1982 to present: Hewitt Camera. Installed 25 October (Wilkins part 1 p.198)