Castlefield Observatory

(1938-72?) Bert Topham's observatory at 1250 Castlefield Ave., Toronto.

Castlefield Observatory was built in Bert Topham's back yard in 1938 and housed a 6½" f/15 refractor.¹ Some information about his observatory and its activities was given in the Chant Medal citation² for 1941:

The dome of his own observatory is of his own design and construction, and is very light, cheap, and serviceable. It is driven electrically by an ingenious method of his own manufacture.

Variable star observing began on 17 April 1937 (JD 2,428,640.6, prior to completion of the observatory), concentrating on "rather faint variables" thanks to the larger-than-average aperture of the telescope. (Topham's observations can be found in this logbook.)

For a time, an original 1868 draft of the Constitution of the Toronto Astronomical Club was pasted to the wall of the observatory, before being rescued and presented to the Society.

Up to 1941, some 3000 visitors came to look through the telescope and receive some instruction in astronomy, mostly on moonlit nights. Most famously, some time after 11 p.m. on the Saturday night (June 1/2) of the RASC / AAVSO 1940 meeting at DDO, a group of rather enthusiastic observers from Milwaukee paid a visit:

Topham was routed out of bed and spent several hours with a group of enthusiasts, demonstrating his equipment, discussing observational problems, and viewing Kodachrome movies of aurora, displayed by Dr. Gartlein in the basement of Topham's home.³

In a letter dated 1944 September 15, Topham writes that a work accident "...cooked both hands for eleven minutes while I hung on to two 550V overhead cables when ladder moved." This accident appears to be an inflection point in the trajectory of his life, with significantly less observing afterwards—at least for variable star work conducted in the observatory.4

The property was sold around 1954 and Bert and his family moved to Brampton.5 Perhaps this was his way of retiring to a less urban setting (the population of Brampton was less than 20,000 in the 1950s) as the property was by now hemmed in on two sides by large commercial buildings. The observatory was abandoned (since it could not have been moved) and the dome was in tatters during its final years of existence. As part of the rapid urbanization that occurred after World War II, all of the land to the north of Castlefield Avenue was developed for commercial use during the 1950s and 60s. Surprisingly, the house and observatory survived until around 1972, when they were finally demolished.6



  1. This telescope was sold to the RASC Montreal Centre in 1957 and housed in their observatory. [ref]
  2. JRASC, 35, 89 (March 1941).
  3. JRASC, 34, 224 (August 1940).
  4. In the letter Topham says that he had just completed a four-month stay in the hospital, which would put his accident sometime in May. This is borne out by the AAVSO International Database where regular variable star observations occur up to JD 2,431,209.5 (April 29) followed by a 321-day hiatus. "I have not [the] power in [my] hands to open my Observatory Dome so [I] will not be able to do telescopic observing until after the final grafting of [my] hands, but, I will do all I can on auroral work..." This would certainly account for the gap.
    He may not have ever fully recovered from his injury ("...the burnt tendons of two fingers of [my] left hand make [the] 3rd & 4th fingers useless..."), yet he did continue to do some observing and photography for the rest of his life. In fact, he resumed observing variable stars 11 months after the accident with increasing annual output until 1947 when he appears to have stopped for good (see here for his annual observation totals).
  5. Bert Topham Recollections, Lynn Kirk, p.7 (in RASC Archives).
  6. Using aerial photos, development in the area can be tracked. Two large commercial buildings appear between 1947 and 1950—one immediately east of the house and one on the south side of the street just a few doors to the west. By 1953, three more large buildings appear immediately to the west. At this point the house and observatory are hemmed in on two sides, and there is evidence of construction of a wide road on the east side of the house to access the undeveloped land to the north. By 1956 a large building appears NW of the house. By 1962, a large parking lot appears north of the house. By 1966 a large building appears east of the parking lot, and by 1967 everything that is not building has been paved.
    The End: The online version of the 1973 aerial photo is rather fuzzy, but it appears that the observatory and house are gone, torn down sometime after the 1971 photo was taken.
    Castlefield Observatory in City of Toronto Aerial Photos, 1947-75:
    1947 | 1950 | 1953 | 1956 | 1959 | 1962 | 1965 | 1966 | 1967 | 1968 | 1971 | 1973 | 1975


Observatory, Castlefield