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The Hopewell Observatory has available a finely-machined antique, brass-tube 6″ f./14 achromatic refractor.

The mount and drive were apparently made by John Brashear, but we don’t know for sure who made the tube, lens, focuser or optics.

We removed a lot of accumulated green or black grunge on the outside of the tube, but found no identifying markings of any sort anywhere, except for the degrees and such on the setting circles and some very subtle marks on the sides of the lens elements indicating the proper alignment.

The son of the original owner told me that the scope and mount were built a bit over a century ago for the American professional astronomer Carl Kiess. The latter worked mostly on stellar and solar spectra for the National Bureau of Standards, was for many years on the faculty of Georgetown University, and passed away in 1967. A few decades later, his son later donated this scope and mount to National Capital Astronomers (of DC), who were unable to use it. NCA then later sold it to us (Hopewell Observatory), who cleaned and tested it.

The attribution of the mount to Brashear was by Bart Fried of the Antique Telescope Society, who said that quite often Brashear didn’t initial or stamp his products. Looking at known examples of Brashear’s mounts, I think Fried is probably correct. Kiess’s son said he thought that the optics were made by an optician in California, but he didn’t remember any other details. His father got his PhD at UC Berkeley in 1913, and later worked at the Lick Observatory before settling in the DC area. The company that Brashear became doesn’t have any records going back that far.

When we first looked through the scope, we thought the views were terrible, which surprised us. However, as we were cleaning the lens cell, someone noticed subtle pencil marks on the edges of the two lens elements, indicating how they were supposed to be aligned with each other. Once we fixed that, and replaced the 8 or so paper tabs with three blue tape tabs, we found it produced very nice views indeed!

The focuser accepts standard 1.25″ eyepieces, and the focuser slides very smoothly (once we got the nasty, flaky corrosion off as delicately as possible and sprayed the metal with several coats of clear polyurethane). The workmanship is beautiful!

Top: tiller for hand control of right ascension. Middle: counterweight bar (machined by me to screw into the mount) with clamps to hold weights in place. Bottom: detail of 1.25″ rack-and-pinion focuser.

We have not cleaned the mechanical mount, or tried it out, but it does appear to operate: the user turns a miniature boat tiller at the end of a long lever to keep up with the motions of the stars.

The mount and cradle (with size 12 feet for scale)

The counterweight rod was missing, so I machined a replacement, which has weight holder clamps like you see in gymnasiums. Normal Barbell-type weights with 1 inch holes fit well and can be adjusted with the clamps.

Unfortunately, the whole device is rather heavy, and we already own a nice 6″ f/15 refractor made by Jaegers, as well as some Schmidt-Cassegrain telescopes that also have long focal lengths. Putting this scope on its own pedestal, outside our roll-off roof, with adequate protection from both the elements and from vandals, or figuring out a way to mount it and remove it when needed, are efforts that we don’t see as being wise for us.

Did I mention that it’s heavy? The OTA and the mount together weigh roughly 100 pounds.

However, it’s really a beautiful, historic piece with great optics. Perhaps a collector might be interested in putting this in a dome atop their home or in their office? Or perhaps someone might be interested in trading this towards a nice Ritchey Chretien or Corrected Dal-Kirkham telescope of moderate aperture?

Anybody know what might be a fair price for this?

Guy Brandenburg


The Hopewell Observatory

Some more photos of the process and to three previous posts on this telescope.

Partway through cleaning the greenish, peeling, grimy layer and old duct tape residue with a fine wire brush at low speed to reveal the beautiful brass OTA.
This shows the universal joint that attaches to the ’tiller’ and drives the RA axis
Do you see the secret mark, not aligned with anything?
Aluminum lens cover and cell before cleaning
Lens cell and cover, with adjustment screws highlighted, after cleaning
It works!