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Julien Peridier Equipment
12.3" Calver; Twin 8" F13 Refractors on Cooke Mount; Troughton & Sims Transit

A little history: Julien Peridier had an observatory in Le Houga, Gers, France. He had a 12.3" George Calver on a #2 Observatory mount; a Cooke mount which he had M. Manent modify to hold two 8" F13 refractors (with optics by André Joseph Alexandre Couder); a Troughton & Sims transit telescope; a massive library; and many other things. Julien Peridier has a prominent crater on Mars named for his contributions to astronomy.

I do have some of the correspondence from Broadhurst & Clarkson when Peridier bought the Calver.

The Calver has quite a history: George Calver made it 1889. It is a 12.3" F6.6 Newtonian on a No. 2 pedestal observatory equatorial mount  It went to an unknown person, then Broadhurst & Clarkson sold it to Peridier in 1931. While at the observatory, it was used by Gerard de Vaucouleurs, and others. 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 1973 Eclipse. Parts of the scope and mount were modified for the expedition. The Peridier Observatory over a number of decades was a recognized observatory with its own research publication series.

The Calver had a 16.75" Byers worm drive installed on it for the trip to the Sahara Desert. I have the original worm gear and drive, but it appears part of the mount was machined to accommodate the new Byers worm wheel. The Calver tube has had several focusers installed on it, as well as many different instruments, because there are lots of holes in the tube. 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 has several places where whoever resilvered it signed it. 

I refer to the other scope as the Cooke/Manent/Couder. It was missing parts. I made lots of bolts, nuts, and other parts. It was hard to tell what all was missing until I started putting it together. Having never seen a mount like it (also being as it was modified, there is not another one like it) I was at a disadvantage. I put pieces on only to take them apart again, over and over. I finally to where I had a piece that wouldn't fit anywhere. It looked like it should go on the R.A axis, but it was too big. I figured out there was a piece missing. It was a piece of brass about 10" OD by 8" ID. I had one piece of brass big enough OD but not big enough ID. I had another close to the correct ID but not big enough OD. So.....I turned both pieces so the smaller would fit inside the larger. Then I put several setscrews between them so they would stay together. Then I turned the piece to the correct dimensions, slit it because it is a brake, and cut a groove for the knob to push. I have assembled the whole thing, and have finished making all the missing pieces. This scope also has a massive filar micrometer. It is mounted on a 3" drawtube. Other accessories also have or fit a 3" drawtube. I found many accessories that would not fit anything, so I made adapters. I found adapters that fit nothing. Someone somewhere has a box of parts that is just the opposite of my box of parts.

For the Troughton & Sims transit, I made the 3 brass leveling bolts. 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 lens cell was badly bent, so I made a new one. I also repaired the focuser and installed new webs.


12.3" F6.6 George Calver, mostly completed. For more pictures go to this page.


Twin 8" F13 refractors on Cooke mount. I call it the Cooke/Manent/Couder. For more pictures, including restoration, go to this page.


Filar Micrometer for Cooke/Manent/Couder The tube replaces the focuser on the faceplate and is 82MM diameter.


Troughton & Sims Transit. It was also part of Peridier's equipment. For more pictures, go to this page.