in 1965, and was dedicated in 1967. On December 1, 1967, the Isaac Newton Telescope of the Royal Greenwich Observatory at Herstmonceux was inaugurated (dedicated) by Queen Elizabeth II. One of the accomplishments with the telescope was the observations of Cygnus X-1. In the late 1960s, a concept was developed for a Northern Hemisphere Observatory, that culminated in the project for an international observatory in the Canary Islands; Mauna Kea in Hawaii was also considered for the location. Although the telescope itself was acquitting itself, the weather at the site less so. This eventually led to the plan to move the telescope to a new observatory, which would occur in the next decade and into the early 1980s. The 'last light' for original Isaac Newton Telescope was in May 1979. The new telescope for the island had so many new parts however, it was deemed possible in the mid-1980s to essentially fork the telescope design into two working telescopes with some rejuvenation. This would mean having another functioning telescope at Sussex, however this project was terminated.One issue is that it would mean operating two telescopes, and the focus at that time had shifted to operating the new INT on the island. The old site would eventually be turned into a science museum with much of the old telescopes left as they were. The old observatory buildings remain by the Castle, and it is the site of the Herstmonceux Science Center (aka Observatory Science Center at Herstmonceux). During construction in 1983, a Spanish container ship carrying parts of the telescope to La Palma was involved in an aircraft incident. In what is known as the Alraigo incident, a British Royal Navy Sea Harrier fighter jet made an emergency landing on the base plate for the observatory. Technical detail since 1984 The La Palma INT is a Cassegrain telescope, with a 2.54 m (100 in) diameter primary mirror and a focal length of 8.36 m (329 in). The mirror weighs 4361 kg (9614 lb), and is supported by a polar disc/fork type equatorial mounting. The total weight of the telescope is around 90 tons. The f/3.29 Prime focus, used with the WFC, allows an unvignetted field of view of 40 arcminutes (approximately 0.3 square degrees). There is also a secondary focal station, the f/15 Cassegrain focus, which possesses a 20 arcminute field of view and is the mount point for the IDS.