History of The Building of
The Stony Ridge Observatory

In 1947, a group of amateur astronomers, including George A. Carroll, Ernest R. Siefkin, and Jerome B. White created The Association of Amateur Astronomers (AAA) for the purpose of:

  • Engaging in the study of the history and science of Astronomy and Astrophysics,

  • To operating a nonprofit organization holding scientific meetings, and conducting research projects,

  • And to assist in the dissemination of scientific knowledge pertaining to Astronomy and Astrophysics

February 1957 - The members of the AAA, then numbering about 15 Southern California amateur astronomers, each committed their time and resources to the completion of an observatory that would house a major instrument for the benefit of amateur astronomy.

An Executive Committee (EC) was formed to be responsible for various aspects of the design and building of an observatory. The committee was given authorization to call on any one of the members for aid, information, or any assistance needed for fulfilling its duties. The first EC consisted of Ernest (Easy) Sloman - Chairman, George A. Carroll - Chief Engineer, Eugene C. Larr - Optical Engineer, and Alan McClure - Expediter. The other members of AAA would associate themselves into the divisions of the EC, thus all members would have a significant part in the completion of the overall project under the direction of a primary accountable leader from the EC.

The group reasoned that by focusing on the building of the telescope first, the completed, or nearly-completed instrument would provide credibility to the successful completion of the whole observatory project. The telescope would serve as a beacon to attract new persons (and funds) to the membership and would give other supporters reason to invest in the project. This initial insight would later prove to be a very important key to the successful completion of Stony Ridge Observatory.

April 1957 - After obtaining advice from Dr. Ira Bowen, Director of the Mt. Wilson Observatory, and Don Hendrix, chief optician responsible for the final polishing of the Hale 200-inch mirror, Gene Larr suggested to the EC that a mirror of a focal ratio of f/6, between 30 and 40 inches in diameter would be appropriate for the design specifications of the new telescope. Larr also had discussions with Dr. Bowen about the future observatory site being located somewhere on the grounds of the Mt. Wilson Observatory. Dr. Bowen, although initially accepting of the idea, said that their insurance policy could not permit the use of their site. Gene Larr had some friends and acquaintances who were professional astronomers and expressed an interest in joining the group. Although he never did join AAA/SRO, the famous Mt. Wilson/Palomar astronomer Alan Sandage did express his interest to join.

Estimates for 30- to 40-inch mirror blanks were obtained from the Corning Glass works in Pennsylvania. An obsidian mirror blank that was available for sale at Tinsley Labs in northern California was also considered but was later rejected because of numerous near-surface bubbles that would require extra work to grind out. Ultimately an order to cast a 30.5-inch pyrex glass blank was placed with Corning for a cost of $1425.

The design and construction of the telescope was the responsibility of George A. Carroll (1902-1987), a pioneer aircraft designer and a well-known instrument and telescope maker in Southern California.

With the cost of the primary mirror known, George Carroll estimated the total cost of the telescope to be $7500, or about $500 per member. It was decided to increase the $5/month membership fee to $10/month to help cover the cost of the telescope over 4 years.

May 1957 - Members not directly focused on the design and construction of the telescope involved themselves with other aspects of the total project. The selection of a suitable observatory site was being pursued by Easy Sloman. On his short list was a 160-acre plot privately owned by a friend of his near Chilao Flats in the Angeles National Forest that might be available for lease, at a cost of about $400/yr. However, 160 acres was certainly more area than needed for our observatory. Representatives with the US Forest Service (USFS) indicated to Sloman that a lease for $100/year could probably be made through a "Special Use Permit" for USFS land that would satisfy our project needs.

June 1957 - Carroll suggested that the estimate of $7500 for telescope was probably too high. An English mount, similar to the mount of the 100-inch telescope at Mt. Wilson, was proposed that could save 30% of the cost of a fork mount for the telescope. The fork mount prevailed because of its convenience of use.

January 1958 - Because of delays and some perceived shady negotiations by Corning Glass, the EC canceled the Corning order and decided to purchase a 30-inch mirror blank from the Hayward Scientific Company in Whittier, CA.

March 1958 - Gene Larr reported that the 30-inch mirror blank from Hayward Glass would be ready to be picked up in April. The cost of the mirror blank was $1420, $5 less than the original estimate given to us a year earlier by Corning. He expressed the immediate need to start construction of a mirror-grinding machine. He and Roy Ensign had the materials to start its construction.

Larr, Sloman and Al Cram were asked to visit alternate sites for the location of the observatory suggested by the U.S. Forest Service (USFS), and to select one ASAP. Larr was authorized to negotiate with the USFS.

April 1958 - The mirror blank from Hayward was cast 2 inches too thick. After assessing the issue and finding it unacceptable, Gene Larr rejected the blank and instructed Hayward Glass to re-cast the blank to our specifications.

May 1958 - After a thorough investigation of possible sites for the observatory, a site near Charlton Flats in the Angeles National Forest was selected because of its good astronomical seeing conditions and its close-in location.

After some intervention by our Congress person, an application for a "Special Use Permit" was filed with USFS.

But... (always a but..., or two) the California Transportation Department (Cal Trans) would not spend public funds on construction of a private road to the observatory site, which was located about 4000 feet off of the highway. Plus, the County of Los Angeles had never before granted a new building permit for an observatory on a remote mountain top.

Eventually an agreement to a plan was made in which some of the road work would be paid for by the County of LA and some by the USFS, and some would be the responsibility of our members. A contractor was selected to build our part of the road up to the site.

September 1958 - Carroll reports that the design for the telescope is completed - next step is to work with George Perkins to come up with drawings and to identify a fabricator for the polar axis and the fork mount. Carroll suggested a truncated cone structure for the dome, similar to the dome for the 24-inch telescope at Lowell Observatory. Larr recommended wood for the structural material and sheathing, noting excellent reports from Lowell's experience. Norrie Roberts, in charge of all the buildings at the site, felt that a hemispherical dome, made from steel supports and aluminum sheathing, while expensive to construct, would be more desirable. After much discussion, Norrie's proposal prevailed.

That turned out to be a crucial decision when, in 2009, the "Station" fire swept over the observatory site - from 2 directions! - without permanent damage to any of the facilities. A wooden dome, as originally envisioned, would not have fared so well.

Larr reported that the rough grinding of the front surface of the 30-inch mirror has begun at his shop in Altadena, CA using a temporary grinding machine.

USFS was still working on the fine print of the "Special Use Permit."

November 1958 - Carroll presents completed drawings of 30-inch, next move is to dole out fabricating jobs to various members, he mentions that he found a machine shop in Burbank (Rene Corporation, owned by John Terlep) that will fabricate the mount/fork parts for free.

January 1959 - Carroll reports further on Terlep's shop, willing to let AAA use space and all machines for free in order for AAA members to fabricate the mount. Terlep joins AAA.

Norrie Roberts, Chuck Buzzetti and John Terlep drew up plans for the buildings and dome at the observatory. These were submitted for the County's approval, enabling us to obtain the necessary permits.

February 1959 - USFS Special Use Permit is approved - 11 months after the application was submitted. Alan McClure leaves the group to work on his own 24-inch telescope project. Roy Ensign reports that work on the new grinding table is completed.

Construction work begins on the new observatory. One of the founding members, Dr. W. H. Griffith, started filming the progress of the project which led to a documentary movie that highlights the construction years at SRO.

March 1960 - Filed an Amendment to the Articles of Incorporation, changing the name, AAA, and creating the nonprofit organization The Stony Ridge Observatory, Inc. (SRO)., The name "Stony Ridge" was suggested by Easy Sloman.

June 1961 - For unknown reasons, Eugene Larr (1927-2006), our Chief Optician, 'disappeared' from the group. Many attempts to contact Gene had not been successful and it became necessary for the SRO Board to find a replacement for this member whom, here-to-fore, had a major role in the early development of SRO. Gene was replaced by Roy K. Ensign to continue as the Optical Engineer to lead the mirror grinding and figuring, which was already underway. By doing an internet search on Gene's name, the author discovered that apparently Gene experience an epiphany after contacts with a minister at a church next door to his Altadena shop, and in 1973 became the first Minister and co-founder of the Chapel of Awareness Spiritualist Church in Encinitas, California. He also continued his astronomy and telescope building interests by teaching amateur telescope making, and making presentations for an amateur astronomy group in the San Diego area.

March 1963 - Roy Ensign reported that the figure of the mirror is correct to within 1/35 wave! - a remarkable figure. This essentially marked the date of completion, prior to aluminizing, for the primary mirror.

John Terlep reported that Norm Bolz has nearly completed installation of the dome rotation system at the site.

Spring/Summer 1963 - At this date, the financial status of the group was thoroughly tapped out. With about $400 in the bank and $1400 in debts, prospects for the completion of the observatory were of great concern to everybody. The most expensive piece of the project was the steel/aluminum dome. Nearing completion at Thomas Tool & Die Company in Sun Valley, the dome still had to be trucked up to the site and with a crane, lowered onto the observatory building.

This SRO dilemma occurred during the era when the United States was preparing a spacecraft mission (Apollo) with the goal of, in the words of President Kennedy, "landing a man on the Moon and returning him safely to the Earth."

Lockheed-California Company had signed a contract with the Aeronautical Charts and Information Center (ACIC) in St. Louis (a section run by the United States Air Force), to supply the ACIC with high-resolution images of the lunar surface for the production of lunar charts that would be used in determining possible landing sites on the Moon. Lockheed then faced a dilemma of its own; where could they find a large amount of telescope time at an observatory to fulfill their contract with the ACIC?

At that time, three SRO members, George Carroll, Norrie Roberts and Chuck Buzzetti worked at Lockheed-California. Through these employee contacts, Lockheed became aware of the nearly completed Stony Ridge Observatory. Lockheed offered a sum of money to the observatory to complete the dome and bring in power and telephone service. For this, an agreement was made between SRO and the aero-space company for SRO to supply the needed telescope time to fulfill their ACIC contract.

August 1963 - Roy Ensign reported that the mirror was at the Mt. Wilson Observatory being aluminized. At this meeting, the members celebrated 1st light with the viewing of Saturn through the 6-inch guide scope.

September, 1963 - The observatory was completed and "first-light" beamed through the Stony Ridge telescope. Upon completion, this superb 30-inch instrument was the eighth largest telescope in California and one of the largest amateur telescopes in the world.


At the end of this 6-year endeavor, the total cost for the Stony Ridge Observatory was about $40,000 in 1963 USD, $2,667 for each of the founding members. The current SRO membership (about 30 members) seems to agree that it would be very difficult to match such a commitment today.

In the years following the successful completion, Stony Ridge has partnered with a number of colleges and universities to provide an environment for their undergraduates to gain experience at a professional quality astronomical facility. A number of scientific projects and outreach programs have been undertaken by the amateur astronomers of Stony Ridge Observatory.

A reminder - Due to its remote location, public access to the observatory is restricted, but anybody can visit the site by invitation only.

scb 2012-03-25
scb 2014-05-17

© 2017 Stony Ridge Observatory, Inc.
A nonprofit 501(c)(3) corporation.