In the early 1930’s Julien Peridier built an observatory in Le Houga, Gers, France, with two domes. One dome contained an 1897 George Calver 12.3” F6.6 Newtonian on a No. 2 pedestal observatory equatorial mount. The other dome contained a large T. Cooke & Sons equatorial mount which he had Maurice Manent modify to hold double 8" refractors (with optics specially made by André Joseph Alexandre Couder [Coudé] ); There was also a Troughton & Sims transit, a host of accessories, a large astronomical library; and many other things. I have some pictures of the scopes as they were in the early 60’s in France. There is a crater on Mars named after him. You will recognize many names in astronomy who visited Peridier and his observatories.
12.3” F6.6 George Calver on N⁰. 2 observatory mount
George Calver made it in January 1897. It went to an unknown person, then in 1931 Broadhurst & Clarkson sold it to Peridier. I have some of the correspondence from Broadhurst & Clarkson when Peridier bought the Calver and the transit scope. While at the observatory, it was used by Gerard de Vaucouleurs from 1939 to 1949 – again in 1959 - and Donald Howard Menzel chose the Le Houga Observatory as one of the sites from which Harvard College Observatory successfully observed the occultation of Regulus by Venus in July 1959. Le Houga Observatory was the site of a five-year NASA program, conducted jointly with Harvard from 1961 to 1965, with multi-color photoelectric photometry of the Moon and planets with the Calver reflector. The book "Harlan's Globetrotters" is the story of astronomers that took the Calver to the Sahara Desert to view the June 30, 1973 Eclipse. Parts of the scope and mount were modified for the expedition. One thing that got my attention in this book was the fact that when they got there, some of the bolts and nuts were missing, and they had to get what they could find locally. There is an article in Sky & Telescope, May 1975, pages 301-306 about this expedition and includes pictures of the modified telescope and mount.
The Calver had a 16.75" Byers worm drive installed on it for the trip to the Sahara Desert. I also have the original worm drive. The steel tube has had several focusers and other equipment installed on it, as well as many different instruments. I did not realize this was a rotating tube until I took it apart for restoration. Where the tube rings attach to the base - both sides were cracked, and I have no idea what kept the tube from falling off. The mirror, which still has the original Calver figure, has been signed by several people who resilvered it.
The tube itself weighs over 450 pounds, and altogether the scope weighs around a ton. It was made in England with Whitworth threads. Julien Peridier modified it somewhat, using metric bolts. When it was modified for the eclipse expedition to Africa, they used S.A.E. parts. By the time I got it, it was a mixture of Whitworth, S.A.E., Metric, and even some custom made bolts and nuts. I made a wedge to make it suitable for my location. A letter in my files states the mirror was tested in 1931, and was found to be excellent.
Troughton and Sims 3” Transit
I made the 3 brass leveling bolts for the Troughton & Sims transit. The lens was missing - I acquired some material from the estate of the late Al Woods, and one of the lenses in a box was exactly a fit physically, and also exactly the correct focal length. The original lens cell was bent, so I made a new cell which the old lens cover fits. I also repaired the focuser and installed new web crosshairs.
The Cooke/Manent/Couder Twin-Tube 8” F13 Refractors
I'm not sure what to call the other scope, which is why I refer to it as the Cooke/Manent/Couder. It is a massive Cooke mount that Peridier had Maurice Manent modify for him. I did not get the R.A. drive with it, but most of the DEC tangent arm was still there. It originally had two 8” lenses by Couder [Coudé] - a photographic, and a visual. The photographic is long gone, but I have the visual. I bought a lens and cell to replace the photographic. This scope, along with the Calver and the transit, was shipped to the U.S. from France in the 60’s. It sat for some time uncrated, so some parts were lost. (Hey look – something shiny, it will fit in my pocket!)
I have not had the bottom half of the pier installed, as it would make the scope way too tall for my shop. I have finished making all the missing parts and adapters. There are some bolts and fittings that don't match up with any of my thread gauges – metric, S.A.E., or Whitworth. The lenses I got were missing some of the adapters, and some adapters did not have lenses to match. It took me quite some time to make all the fittings to be able to use the eyepieces and accessories. I keep thinking someone, somewhere, has a box of eyepieces and adapters that don’t match.
I installed a new Byers 15.1" 359 tooth drive, and made parts and controls to operate the tangent arm. In addition to having many pieces missing, some pieces were bent or threads damaged beyond repair. I made new parts as needed. There is a massive filar micrometer, and two smaller ones. The faceplate accepts drawtubes of about 3” diameter. You remove the focuser which has its own 3” drawtube, and the micrometer has its own 3” drawtube to fit in the faceplate. The focuser accepts eyepieces and accessories with drawtubes of just under 2”. I made more tubes and adapters for my own accessories.
One piece I could not figure out was the “ring”, which looked much like a smaller tangent arm. It did not fit anything, nothing even looked close enough to make me think it went there. I emailed the owners/museums/observatories that had Cooke mounts, but none were like mine as Manent had modified it. I finally found one Cooke mount similar enough to get an idea of how the “ring” should go on. There was a piece missing. I could not find the correct size I.D. and O.D. of round brass to make the missing piece. I had two pieces of brass – one too big, one too little – I turned the I.D. of one and the O.D. of the other and put one inside the other. Then I drilled and tapped holes for setscrews, and used red Locktite. Then I turned the new piece to the correct I.D. and O.D., and cut it to length. I cut a step on the outside for the keeper and cut a slot so the new piece could bend to act as a brake. Somewhat more difficult than it sounds. Now all the pieces are made, new bearings installed, and it is in pieces again, waiting for us to find a new location where I can reassemble and use it. These scopes require massive counterweights. One crate contained several hundred pounds of lead counterweights, and there are several places on the tubes and mount to add weight to counter added instruments such as cameras, filar micrometers, etc. It took a while to figure out how everything goes together, as it has been in pieces since the 60’s. The pictures help, but there was not a picture of every piece.
This was quite the project so far. I still have to paint the scope and mount, and build an appropriate observatory. I look forward to using and sharing these treasures. One last thing – after moving these scopes hundreds of miles, then back and forth between the observatory and the shop - my wife says “if a scope isn’t heavy it isn’t worth owning.”
I have many more pictures and a detailed description of the work I did, this is a condensed version.