Built in 1891 to house a small reversible transit instrument, the Transit Pavilion occupied a prominent postion in the Courtyard until the end of the 1950s when it was demolished.
The centre of the observing pier was 19 feet west and 70 feet north of the Airy Transit Circle. The whole structure was supported on a concrete foundation 1 foot 6 inches deep under the pier and walls and 6 inches deep in the intervening space. The pier was of brick with a capping stone on the top, the total height above the foundation being 8 feet 9 inches. The observing platform was raised 3 feet 3 inches above the floor level serving as a convenient table for the chronograph and signalling apparatus. The space under the platform was used for the storage of batteries. The pier was isolated from the observing platform and floor and protected from accidental jars by a wooden framework round it. The roof consisted of a pair of semi-domes that slid apart to give an opening of 2 feet 6 inches in the plane of the meridian, semi-circular in section.
Work on the Pavilion commenced in the spring of 1891, but took longer than anticipated because of problems with the semi-domes. Meanwhile, a temporary canvas tent was erected over the telescope until these were finally put in place in October 1891. A small transit telescope from the Transit of Venus expeditions of 1874 and 1882 was mounted on the pier. There are records of Transits B, C and D being used there.
In 1927, time determinations with the Airy Transit Circle ceased, transferring instead to the instrument in the Transit Pavilion. The observatory owned five identical small transit instruments and the one in the Pavilion was occasionally swapped for another.
In 1954, as the working Observatory was in the process of moving to Herstmonceux, the Department of Works drew up proposals for the future use of the buildings and grounds. They show that at that time, the plan was to retain the Transit Pavilion as part of the proposed Museum of Astronomy and Navigation. During 1959, after much double-checking, a final decision to demolish the Transit Pavilion was made towards the end of the year. Its actual date of demolition is not recorded, but was probably a few months later in early 1960.
The two images at the top of this page are © BT Heritage. They have been obtained from The BT Digital Archives and are reproduced under the terms of a Creative Commons Attribution-Non-Commercial-ShareAlike (CC BY-NC-SA) licence. They are more compressed than the originals.