The Domes of Morgan Observatory
Ronnie Morgan, June 23, 2001
I have been an avid reader of Sky and Telescope since 1947. In an issue of Sky and Telescope in 1951 or so, I saw an ad for J. O. Paulsen, metal fabricators. I sent for a brochure. In the brochure were a number of photographs of completed observatory domes and a price list. The price of a 10-foot dome was about $ 1,500, a considerable sum of money in those days. We had also sent for a brochure from Tinsley Laboratories of Berkeley, California. They made mostly small refractors of about 3-inch to 4-inch aperture. They also made 8-inch, 10-inch, and 12.5-inch Dall-Kirkham Cassegrain reflectors. I remember vividly that the 12.5-inch f/16 cost $ 3,480.
When my parents built their home in the Country Club Estates east of Odessa in 1952, there were three other homes already located there: Dr. Rich, a dentist, Mr. Redmond, co-owner of Redmond-Nease Buick on East 2nd Street, and Joe Coleman, the Odessa High School football coach whose 1946 Bronco team won the Texas State Championship. I heard a rumor that the home was built and paid for by fans from Odessa. Dr. Rich owned the property with Dr. Hestand, and they subdivided the land into about 1-acre lots. Mr. Redmond owned the home built immediately to the south of my parent’s home. There was electricity provided by Texas Electric Service Company (“Reddy Kilowatt”) and natural gas, but no water or sewer. The streets were paved much as they are today. We had about a 200-foot deep well drilled. Since the electric service was so unreliable, my father had a natural gas powered LeRoi generator installed in the pump house, so we always had electricity and water.
When the dome arrived from J. O Paulsen, we were disappointed to find that it was not a complete dome, but only the rolled steel structural members. The owner was supposed to find a welder to weld the members together, and weld 1/8 X 2-inch cross members. Then, the owner was to rivet the aluminum skin onto the structural members and cross-members. At about Christmas, 1952, James C. Corn, Assistant Director of Morgan Observatory, came to visit from Phoenix, Arizona. He was a very practical man who knew a lot about domes. I remember taking him out to a rusting pile of cold-rolled channel irons, thinking these would never become a dome. He just laughed and told us what we would have to do. The next day, we contacted Austin Sheet Metal Company of Odessa. They sent out a Mr. Davis to look at the dome. When Jim Corn explained what a dome was, how it worked, and how to put it together, Mr. Davis lit up and said, “I know just what to do.”
Mr. Davis soon came out with his welding crew and carefully welded
the structural members to the horizontal track. He also welded together
the lower track. The lower track was installed onto the small cylindrical
structure that protruded above the roof of the guesthouse. The horizontal
members were welded onto the structural members of the dome skeleton and
the aluminum sheeting was riveted onto the structural and cross members.
The whole completed dome was lifted onto the roof of the building by an
A-frame gin pole truck so it fit on the lower track and the casters.
The dome rotated smoothly as soon as it was placed on the track.
The dome was rotated by a rubber tire driven onto the inside of the upper
track of the dome. The dome soon began to slip away from concentric
to the lower track. Other rubber wheels were installed to keep the
dome in alignment. Because of the West Texas wind, angle irons were
welded on the lower track to keep the dome tied to the building.
The whole process took less than a week.
We had a star-shaped set of Christmas lights attached to the apex of
the dome for use as a Christmas decoration. (I will send you a photograph
of the dome lit up at Christmas)
Lloyd Nolan Construction of Wichita Falls, Texas fabricated the home and guesthouse. An architect whose name I do not remember designed it. The guesthouse was designed for the dome. In the center of the building was a 10 X 10-inch cross section pier on which the telescope mount was to rest. Under the building is a 3 X 3-foot block of reinforced concrete. On the side of the guesthouse away from the main house were a bedroom-dining room, bathroom, and kitchenette. On the side of the guesthouse toward the main house was the observatory office, with built-in desk and bookcase. A steel staircase (quite steep) led through a trap door from the office to the observatory on the second floor. When the 12.5-inch Cassegrain telescope was installed, the pier shook and made observing difficult, photography impossible. My father had the builder take out a section of a closet in the guesthouse and a 20-inch cross-section steel structure was installed and concrete poured inside it and around the 10-inch pier. This solved the vibration and shaking. The floor of the observatory was isolated from the pier, so the observer could walk around without shaking the telescope.
In 1953 or 1954, my father began thinking about a larger telescope. He asked Tinsley Laboratories how much a 20-inch or 24-inch reflector would cost. They estimated a 24-inch at $ 15,000. He specified a two-pier English type equatorial mount. He got the idea from the 82-inch reflector at McDonald Observatory. At that time, on the third Thursday of each month, the public could get tickets to observe a few seconds through the 82-inch. We went many times. My father was impressed by the stability of the mount, after the experience with the shaky pier of the 12.5-inch reflector. The 24-inch was a classical Cassegrain with f/4 Newtonian, f/16, f/32, and f/100 Cassegrain secondary mirrors.
Ligon Construction of Odessa constructed the concrete block building for the 24-inch dome. A local surveyor took a Polaris shot at night to determine true north for the piers. The piers were about 2-feet cross section at the bottom and 1-foot cross-section where the telescope mount was affixed. By the time the big dome was constructed, Mr. Davis had left Austin Sheet Metal and started his own business, Metal Specialties, Inc., located at 3345 Kermit Highway in Odessa. I do not know if Mr. Davis is still in business, but he was in 1992 and feeling his age. Mr. Davis knew from the 10-foot dome for the 12.5-inch telescope how domes were constructed. He had the structural members cold rolled by a steel fabrication shop in Houston. Mr. Davis engineered and constructed the rest of the dome. The telescope was in operation by late 1954. It was moved in the late 1950’s or early 1960’s to Lowell Observatory in Flagstaff. My father tried to give the dome to Lowell Observatory along with the telescope, but Lowell was insecure about moving the dome. Mr. Davis offered to cut the dome in half and have it moved to Flagstaff, where he would reconstruct it. Instead, Lowell had a pivoting roof building constructed on a higher elevation point on Mars Hill in Flagstaff. It was too windy there, and the seeing was poor. The instrument was later moved into the 13-inch astrograph dome (the Pluto Telescope), since that instrument also had a two-pier mount about the same size as the 24-inch reflector. When the Pluto Telescope was restored in 1993, the 24-inch telescope was taken out of service and put on display in the Visitor Center at Lowell Observatory. I understand that the 20-inch apochromatic lens is also on display there.
The dome for the 20-inch f/16 apochromatic refractor was installed at Lake Thomas, near Snyder, Texas. Again, Mr. Davis of Metal Specialties built the dome. Ligon Construction of Odessa built the building. It was 32-feet in diameter. The telescope tube was 27-feet long. The telescope was mounted on a German equatorial mount with 4.5-inch tubular steel shafts. The floor of the building had concentric stair steps to allow access to the eye end of the tube at high altitudes of observing. A steel motorized chair lift was designed and constructed to allow access to the eye end of the tube for low altitudes of observing. In the center of the tube, where it attached to the mount, was an electronically actuated shutter for high-speed photography of the moon. The objective end of the telescope tube had an iris diaphragm that would stop the telescope down to about 12-inches effective aperture.
Again, the dome was built by Mr. Davis of Metal Specialties, Inc. of Odessa. It was of the same construction as the other domes, except notably larger. When Lowell Observatory bought the telescope through a grant by the Aeronautical Chart and Information Center, the dome was cut in half and moved to Flagstaff. There it was reconstructed. Mr. Davis also built a dome for McDonald Observatory and one for an observatory in Hawaii. He may have built one or two others. He claimed (in a conversation in 1992) that he never made any profit on any of the domes, but he enjoyed the challenge of building them.
There was one other interesting instrument that was a part of Morgan Observatory. In 1953, Mr. F. L. Goodwin of Chicago wrote to my father to state that he had a 9.5-inch f/13.3 doublet refractor for sale. A Mr. Jeslerski, an unknown telescope maker, built the instrument in the 1920’s. Mr. Goodwin was the person who made the Barlow lens popular among amateurs in the 1950’s and 1960’s.
We bought the refractor and it arrived in Odessa by motor freight. It came with an unpainted steel tripod that was covered in rust. The brass and bronze tube and focusing system were badly corroded with a green patina. An employee of General Machine (Dale Clinton) and I spent several weeks sanding the tube and polishing the bronze machined parts. At last, we coated the entire assembly with lacquer and installed the objective. The optical quality of the objective was superb, and the ship’s wheel focuser was also impressive. On the old tripod, however, it was unwieldy and hard to follow diurnal motion with that size instrument on an altazimuth tripod. The objective was slightly under-polished to diminish the chromatic haze produced by such a large fast doublet objective. The refractor was installed on the 24-inch reflector as a guide telescope. The length of the tube was such that it nearly filled the dome. When the 24-inch was donated to Lowell Observatory, they had no use for it. When the 20-inch apochromatic refractor was built, the 9.5-inch was installed as a guide telescope. When Lowell Observatory purchased the 20-inch, they took the 9.5-inch as well. The apochromatic telescope has been removed from the mount for some years and an 18-inch Baker-Nunn camera mounted in its place. The 9.5-inch Jeslerski refractor is still installed on the mount as a guide telescope. Some of the finest photographs of the whole Moon made at Morgan Observatory were made through the 9.5-inch refractor.