who praised the Observatory as "a gift to science all over the world". Chant retired the same day and moved into Observatory House, the original pre-Confederation farmhouse (built in 1864 for Alexander Marsh and known also as Elms Lea Alexander Marsh) just to the south of the administration buildings, where he spent his remaining years. In May 1939, the train carrying King George VI and Queen Elizabeth, the Queen Mother on their cross-Canada tour paused on the railway below the observatory, the largest telescope in the commonwealth. Grubb-Parsons built four more 1.88-metre telescopes with similarities to the instrument in Richmond Hill: for Radcliffe Observatory near Pretoria, Mount Stromlo Observatory in Australia, Helwan Observatory in Egypt, and an observatory in Okayama Prefecture in Japan. The South African instrument was disassembled and moved to Sutherland, Northern Cape in the 1970s because of light pollution. The original telescope mirror at Helwan was replaced by Zeiss in 1997, and the telescope at Mount Stromlo was destroyed by fire in 2003. A 1.93-metre Grubb-Parsons telescope at Haute-Provence Observatory with a higher-resolution spectrograph was used to discover an extrasolar planet orbiting the star 51 Pegasi in 1995. The three smaller domes at the top of the DDO administration building are used for smaller instruments. Soon after the observatory opened in 1935, a Cassegrain reflector telescope was installed in the southern dome. The Cooke Refractor had been out of use since the Meteorological Office had given it to Hart House, but it was little used and was moved into the northern dome in 1951 to be used by undergraduates. In 1965, a similar Cassegrain was added to the central dome. Operations From 1946 to 1951 the observatory director was Frank Scott Hogg, who was joined at the DDO by his wife Helen Sawyer Hogg. After her husband's death, Helen continued at the observatory, surveying globular clusters to gauge their distance, publishing a major catalog of variable stars in clusters. Her weekly 'With the Stars' column in the Toronto Star was published from 1951 to 1981. In 1959 and 1966 staff astronomer Sidney van den Bergh composed a database of dwarf galaxies known as the David Dunlap Observatory Catalogue. In collaboration with the Department of Electrical Engineering, Donald MacRae established a radio astronomy observatory on the observatory grounds in 1956. The DDO work led to the 1963 measurement of the absolute flux density of Cassiopeia A at 320