François Terby: a Leuven amateur astronomer 140 years ago
Much as a surprise to many Leuven inhabitants, once upon a time, all the way back to 1884, there lived an avid amateur astronomer called François Terby. He invested an enormous amount of money to build a 3-story observatory (brick walls, wooden dome) next to his house in the Bogaarden street.
His observations were mainly planetary, Jupiter and also Mars. Many drawings are available, and he corresponded with Schiaparelli in Milan about the ‘canals’ on Mars. His enthousiasm was such that he also could confirm these so-called-channels.
On May 23th, I could visit the Leuven city archive, and some surprises came up:
- The 8″ refractor telescope was always called by Terby himself as a “Grubb” telescope, now it is unmistakenly mounted on a Thomas Cooke telescope mount.
- The observatory was not just a roof add-on, but a substantial seperate tower, including a proper foundation and a wooden dome, about 4 meters in diameter.
Now the hunt is on for the lost refractor. In 1961 the observatory was demolished.
The observatory was a brick building – 3 stories high, it was build on the street side to the left of the existing family home.
The location corresponds with a small white circular disk, that is visible on a 1947 aerial picture of Leuven.
A picture of the building plans, as available in the Leuven city archive:
It’s not clear from the plans, if the central column was free-standing, or if it was braced as seen in the cross-section (in red, below left) – all the way up to the upper floor. Remarkable is also that the lowest part of the column (below ground) seems to be smaller in diameter. that would make no sense, from an engineering point considering stability.
War Damage?
First message were that no files were logged for war damage for the address Bogaardenstraat 70 in Leuven. Now it seems that three different files are available, and logged by Mr. Terby ‘s wife after WW I during the 20’s. The finder of these files (I. Jorissen) is likely going to consult these files.
Stroobant
Mr. Stroobant wrote a book on François Terby, with lots of interesting details. It can be consulted online (Google both names). Main takeways are:
- before the 8″ Grubb refractor Mr. Terby used a 90mm Secrétan refractor. However it appears that between these two telescope, he also used a 109mm Secrétan !
- Terby did not only correspond with letters to the Royal Belgian Observatory, he actually also did some observations there (old observatory in the city).
- he did some ‘shooting stars’ observing also, from Leuven, and this with his friend ‘ingenieur Van Lindt’.
- he could see bright zodiacal light from Leuven centre.
- his interest started during his high school years, in the ‘Josefieten’ (old market), where a teacher had a small refractor
- his oldest son was a math teacher in the ‘Atheneum” in Leuven
However! not one single word on the destiny of the Grubb telescope.
This picture comes from an RAF aerial survey in 1947. The observatory dome can be identified as a white disk on the location in the Boogaardenstraat. before it was clear that the observatory tower stood to the left side of the current house, the location was a bit odd, as the expectation was that the observatory dome would be in the garden behind – or simply on the roof or backside of the house.
