AAAP member John Seiple had already donated a long focal length 10" mirror for the club telescope. To make observing as comfortable as possible for visitors, Leo decided to install a unique telescope mount he had seen at a Springfield, Vermont convention. The "Springfield Mount," as it came to be known, directed celestial light through a series of prisms and lenses built into the equatorial mount, thus allowing the eyepiece (and the observer) to remain stationary, regardless of the position of the telescope tube. Leo commented, "I liked the design because it prevented the observer from having to assume all sorts of arthritic positions."
Leo tries out his unique eyepiece configuration on the Springfield mount
He built the basic mounting from iron castings procured from John Pierce of Springfield, then took the castings to a John Klager on Perrysville Avenue to have them machined. The tube assembly utilized an octagonal cross section made from 1/8 inch aluminum. Leo designed the telescope's 2-ocular revolving eyepiece holder while he was idling the time away during jury duty, and enhanced the design of the mount with his own "non-sway" counterweight system. Readily detachable pieces, including the mirror, were removed when the telescope was not in use, and the remaining assembly covered with a tarp for weather protection.
However, the initial installation of the Springfield Telescope suffered from several perplexing problems. For example, light pollution from nearby street lamps interfered with observing in almost every direction. Leo tried various methods to eradicate these lights, including (and this is typical Leo Scanlon apocrypha) paying 10 cents to a local "street urchin" to shoot them out with a sling shot. "The city replaced the lamps with maddening regularity," he said.
He also tried blotting out the facing side of the street light with a shoe polish brush at the end of a clothesline prop, only to have it washed away during the next rainstorm. Failing that, he set up a blank screen made of beaver-board between the offending street light and the observing deck; but this did nothing for the numerous more distant light sources in other directions. The only permanent solution was to build an observatory dome on top of a 4-wall wood frame (board-and-batten) structure. Leo also believed that a fully enclosed observatory would also prevent careless visitors from possibly falling off the edge of his workshop roof in the darkness! And he liked the idea of not having to disassemble the telescope and cover the remaining parts after every time it was used.
Having decided to build a domed observatory, Leo and his associates decided to take the opportunity to construct a new type of sheet aluminum shell which would be lighter weight, easier to fabricate and less expensive than the other more complex dome designs of the time (see the Valley View Construction Saga for more details). In retrospect, Leo had already vaguely considered financing and building such an observatory anyway, irrespective of the local observing problems. "Keeping all the above reasons in mind, but really needing none of them, as we would have built the dome anyhow, just for the fun of it, we decided to erect a headquarters for the Astronomical Section of the Academy of Science & Art of Pittsburgh. Of course, this sounds rather pretentious, and would suggest that we had unlimited funds at our disposal, but as a matter of fact the money came from but one source which had been established some time before by me, unknowingly for just such a time. Well, we didn't have to go very deeply into the old sock at that."
Leo's project received strong and consistent support from the start. An AAAP associate who worked for Alcoa provided the raw sheet metal, while another member, a math professor from Carnegie Tech (now CMU), performed the computations needed to lay out the cutting patterns. Trimming and assembling the "orange peel" sections was a tour de force of geometric precision. Twelve panels or "gores" were produced, one for each zodiacal constellation. Leo employed a joint-coupling method, known to roofers as a "double-turn standing seam," which eliminated any need for mechanical fasteners or supporting ribs. He recalled that he had the easier part of the assembly job: Hammering the seams together from the outside while others (including brother Frank) backed up the joint from the inside, where the sound of the hammering was trapped and amplified.
Some people were initially concerned about the structural strength of the new dome, including Alcoa which warned him not to climb on top because it would "shimmy like a hula hoop under the weight," as Leo recalled it. He promptly climbed on top of structure, had himself photographed and sent the photo to Alcoa to prove them otherwise.
The completed dome for "Valley View Observatory" was the first in the world to be made entirely of aluminum, and became the model for many other domes since. In time, Valley View was featured in the book Amateur Telescope Making Advanced, a publication of Scientific American magazine. In the introduction to this chapter Leo commented: "... a permanently mounted instrument, protected by an observatory of whatever type, is ready for use at all times at a moment's notice; it is almost axiomatic that one cannot become fully acquainted with the whims and possibilities of a portable telescope in less than a year's service. This time could be fractionalized in an observatory, and consequently, greater appreciation of the telescope would ensue and a longer useful observing life result."
Amateur astronomers from Texas and Canada requested blueprints of the Valley View design, which Leo furnished, but it is not known if the specific design was ever actually duplicated. Years later, when it was time to dismantle the observatory, Leo said of all the attention it received: "I didn't think it was so wonderful. It was something I had to do."
Local news media interest in the 10" Springfield telescope was intense, in part because astronomical telescopes at that time possessed a certain mystical quality, despite their simple design and operating principles. Asked how he built such a marvelous device, Leo told one awe-struck reporter: "I didn't need to buy a single tool to erect it….All the planes, hammers, saws and files I use in plumbing came in just right for putting the ‘star seeker' together. Every amateur instrument builder runs into situations where he must invent a tool or improvise a metal fitting. I would have been deadlocked many times if I hadn't had experience in working out our plumbing problems."
Among the visitors to Valley View Observatory were faculty members from Bethany College in West Virginia. They were so impressed with the 10" Springfield and its motor drive that they purchased the instrument for use at their school as a naval navigation training aid (the telescope would be rediscovered 60 years later at Bethany and returned to the Pittsburgh area). "They wanted to purchase the building too, but I demurred," said Leo. After the 10" Springfield was removed, Leo replaced it with an 8" Cassegrain reflector which could be moved from the observatory's permanent mount to an outdoor tripod when needed (Leo donated this instrument to the AAAP in the early 1990's).
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