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Authors: Ronald Florence

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Opticians at the Mount Wilson optical labs figured the twenty-four-inch mirror and eighteen-inch correcting plate for the new Schmidt camera. The Caltech astrophysics machine shop built the tube and mounting. Russell Porter’s design looked like an eighteenth-century cannon mounted in a tuning fork. The correcting plate was at the muzzle of the cannon, protected by shutters that opened and closed to control the exposure of the film. The film holder inside the camera was reached through a door in the side. The machine shop built film holders that would cut the photographic emulsions in a circle and bend the emulsions so their curvature exactly matched the spherical focal curve of the camera.

As the eighteen-foot-diameter dome went up at Palomar, experienced Mount Wilson workmen came up to install the new telescope. Jerry Dowd, the master electrician from Mount Wilson who had wired the electric controls for the solar telescope in George Hale’s laboratory, did the wiring. Dowd had retired from the observatory to a ranch, until he heard about the new work going on at Palomar. He couldn’t resist the opportunity to wire another telescope, even though he was only paid the same sixty-seven and a half cents per hour that the regular construction workers received. Ben Traxler got the job of helping the mechanics and technicians from Pasadena do the installation and learned the tricks of slip-couplings for the rotating dome and the complexities of wiring for telescopes.

By the fall of 1936, the Schmidt camera was in operation. One of the cottages on the mountain had been rushed to completion for Zwicky’s use, and he began making the trip from Pasadena to Palomar to photograph galaxies, searching for supernovae. Byron Hill met Zwicky on one of his first trips up the mountain, in a heavy snow. Hill had sent the Caterpillar tractor with a chain to pull Zwicky’s car. Zwicky wanted rope instead of the chain, and before long they were in a full-scale argument. To Zwicky, Hill was one more “spherical bastard”—no matter which way you looked at him, he was still a bastard. The astrophysicist recruited Ben Traxler as his night assistant on the telescope, and soon Zwicky would signal his arrival on the mountain each night with a shout of
“Wo ist
Traxler?” That slight of protocol, circumventing Hill’s authority as superintendent on the mountain, didn’t sit well with Hill. The politics of the mountain began early.

Zwicky, in his first films of galaxies in Virgo, found supernovas. He
kept up the search, pushing and tugging at the sometimes balky Schmidt camera until its battleship-gray tube was dented with scars. Zwicky still holds the record for the most supernovas recorded by a single observer.

In Pasadena the arrival of the disk, coupled with Sandy McDowell’s eagerness to begin the actual construction, put the final stages of the design of the telescope in high gear.

Once the yoke mounting, with a giant horseshoe bearing to support the weight at the north end of the telescope, had been selected, the pieces of the design began to fall into place. Mark Serrurier, who had been given the challenge of designing the tube of the telescope, had fiddled with his pencils until he stumbled on an idea so elegant and simple that engineers who looked at his drawings shrugged and asked, “Why didn’t I think of that?”

Serrurier knew that the weight of the mirror in its cell at one end of the tube and the prime focus cage, with equipment and auxiliary mirrors, at the other end of the tube, made it fundamentally impossible to design a telescope tube that wouldn’t flex. He kept playing with Martel’s suggestion that the tube didn’t have to be absolutely rigid, that what mattered was for the primary mirror at one end of the tube, and the correcting lens or auxiliary mirror at the other, to be perfectly
aligned
with each other. If both ends of the fifty-seven-foot-long tube drooped, even as much as one-sixteenth of an inch (an enormous distance at optical tolerances), it would not affect the alignment of the mirror and the prime focus as long as both ends drooped the same amount and remained parallel to each other.

Suddenly the problem was much simpler. Serrurier sketched supports that ran diagonally from the corners of the tube to its central pivot point. Compared to the massive braced girders that had been used for previous telescopes, the supports seemed airy. But the diagonal supports meant that any motion of the ends of the tube would create compression in the supports. Try to compress a rod, as opposed to bending it, and the effect of Serrurier’s structure is immediately clear. The ends of his tube would droop by a millimeter or so, but the diagonal struts would keep the two ends parallel and perfectly aligned. The elegant, symmetrical structure immediately earned the name Serrurier truss. In various forms it was soon widely copied for telescopes and other structures.

One major question remained for the telescope: the bearings. The entire weight of the moving portions of the telescope, half a million pounds, would rest on the north and south bearings of the yoke. Francis Pease’s drawings still showed huge roller bearings for the north bearing under the horseshoe, but the horsepower needed to move the telescope on roller bearings, and the potential distortion of the rollers
from the heavy load, were discouraging. Ball bearings were worse. Even the declination bearings for the telescope tube presented problems. Serrurier’s new design, which lightened the tube, still concentrated the full weight of the tube on the declination bearings.

Sandy McDowell, who had been brought into the project to supervise construction, was eager to move from design to actual building. His experience in the navy had been with large welded components, and he wanted to have as much of the telescope as possible built from seamless, welded construction. Especially if the welded sections were annealed—a process of heating and controlled cooling, similar to the annealing of a glass disk—which would remove residual strains in the steel, the telescope would emerge a strong, monocoque structure, with no danger of fastenings loosening or corroding.

Some consultants argued that a welded structure would be
too
stiff, that riveting the members together would permit a flexibility that would slow down or dampen vibrations in the structure. Welding, by increasing the rigidity, would shorten the period of vibrations, increasing the number of cycles per unit of time. The welding advocates argued that vibrations would only be a problem if they didn’t get the drives and mount right. They had worked long enough on this project that they
would
get it right. Finally even Pease, the traditionalist among the design staff, came around to the welded construction.

Welded fabrication had another appeal for the project. It was fashionable. In place of the bolts and rivet heads of the Mount Wilson telescopes, a welded telescope would be sleek, smooth, and streamlined, like the new aerodynamic designs that were just being introduced in automobiles and locomotives. An earlier era had marked its technology with the strength of massive raw-steel construction, producing the Brooklyn and Golden Gate Bridges and the massive riveted and bolted frames of skyscrapers. Welding not only offered the technical advantages of fusing the metal fabrications into large, strong structures but created a look as modern as that of the sleek cars that graced the pages of
Life
magazine.

There were few companies with experience of welding large structures, and even fewer engineers who had the experience of designing large structures to take advantage of welded joints. The telescope added the additional requirement that many surfaces of the structures had to be machined to extremely fine tolerances. McDowell concluded that only companies with experience building large hydroelectric turbines and heavy gun turrets combined the two skills. He approached the men he knew: Wylie Wakeman, general manager of Bethlehem Shipbuilding; Homer Ferguson, president of Newport News Shipbuilding; J. F. Metton, president of New York Shipbuilding; and W. W. Smith of Federal Shipbuilding. When they turned him down, McDowell approached the commander of the Mare Island shipyard in San
Francisco, asking whether they could do the final machining on the mounts if someone else did the fabrication. None of the companies he approached had any experience with telescopes.

When the shipbuilders turned him down, he went to companies with experience on hydroelectric turbines and other heavy structures. George Hale had already begun preliminary negotiations with Westinghouse and Babcock & Wilcox, who had both done large welded structures for the Boulder Dam. General Electric had done some heavy welded structures for electrical systems in Russia. Baldwin-Southwark Corp. built locomotives. The American Bridge Company, Warner & Swasey, Budd Steel, and Inland Steel were all interested. Westinghouse sent a vice president, the manager of their huge South Philadelphia plant, and a group of engineers to meet with McDowell. Except for a few government projects, like the Boulder Dam, their business had been slow. The end of 1935 and 1936 seemed an opportune window to keep some idle factory capacity busy.

While McDowell was negotiating to decide who would build the mounting, the preliminary plans were sent to a blue-ribbon list of independent consulting engineers: S. C. Hollister at Cornell, George E. Beggs at Princeton, W. F. Durand at Stanford University, S. F. Timoshenko of the University of Michigan, John Lessells and George B. Karelitz of Lessell & Karelitz in New York City. The consultants unanimously supported the horseshoe design.

By the end of 1935, McDowell contracted for the first large fabricated component, the cell that would hold the mirror, which he ordered from Babcock & Wilcox, who had taken on Baldwin-Southwark as a partner on the proposal because a portion of the machining was so large it would require an oversize boring mill at the Baldwin Locomotive Works. On his trips east, McDowell also held more talks with Westinghouse. Their huge South Philadelphia plant built ship turbines. They had lathes, milling machines, and boring mills large enough to machine the biggest components of the telescope, spare capacity in the plant, and an engineering staff with experience on welded structures. Jess Ormondroyd, the manager of the experimental division at Westinghouse, agreed to send a Westinghouse engineer out to California to work on the details of the mounting.

Rein Kroon was the youngest engineer on the staff at Westinghouse. A Dutchman, he had graduated from the Federal Technical Institute in Zurich, couldn’t find a job in Europe, and was hired as a design school student with Westinghouse by Timoshenko and Lessells, both consultants on the Palomar project. Kroon had been too young to enter the Federal Technical Institute when he first graduated from high school, so he had spent a year working as a volunteer in a Swiss factory. Under the Swiss apprentice system, as soon as a worker
announced that he had spent long enough in a job, he was moved to a new position. For a quick learner, a year of apprenticeship meant a wide exposure to machine work.

Kroon was newly married, with a one-month-old son, when he was told that he would be temporarily assigned to a project in Pasadena, California. He hadn’t heard about the telescope project—the newspapers in Europe were too busy with Hitler, Mussolini, and the abdication of the king of England to chronicle an unbuilt American telescope—and he had to look up Pasadena in an atlas to see where he was going. He carried his son on the train in a basket.

When Kroon got to Pasadena, McDowell had arranged a welcoming party and found Kroon and his family a bungalow on Los Robles Avenue. The next day Rein Kroon, a tall, lanky man with a soft voice and a remarkably soothing accent for a Dutchman, showed up at the astrophysics laboratory, where he was given an office with a drawing board and a stack of sketches and drawings.

Kroon had an odd advantage over everyone else on the project. Almost everyone who had worked on the telescope had some experience as an astronomer and ideas of how a telescope
should
be built. Kroon had never worked on a telescope before and hadn’t even seen a large astronomical telescope. He saw every problem of the project as a challenge in pure engineering. It didn’t matter if the project was a telescope or a jet engine: Engineering was problems to be solved.

The first problem they handed Kroon was the horseshoe bearing. When he came to Caltech, McDowell had asked around about an idea that had been discussed in the navy—the possibility of using a thin film of oil, under pressure, as a bearing for the weight of the telescope. Pease, pushing for roller bearings, dismissed the idea as impractical. McDowell, who had his doubts about Pease, solicited opinions on the idea from outsiders. J. Emerson, from the navy shipyard at Mare Island, recommended against oil bearings: There were too many variables to control, such as temperature and the viscosity of the oil; it would be too hard to keep out vibrations and tremors; it would require considerable power; and any movement or slippage would wear grooves in the bearing surfaces that would effectively destroy them. As an illustration that the bearings couldn’t work, he suggested the experiment of putting a playing card on a spool; no matter how hard a person blows, he cannot lift the card. Like Pease, he preferred the roller bearings.

In fact, the only real interest in the oil-bearing idea came from Guenther Froebel, an engineer at Westinghouse, who thought that if the problems could be solved, oil bearings would be simpler and smoother than roller bearings. No one else wanted the problem of trying to design an oil pressure bearing, so it was given to the new man.

Kroon began by going over the calculations that had already been done. Francis Hodgkinson, the chief engineer at Westinghouse, had
done some preliminary work on oil pressure bearings for the heavy rotors in power turbines. The idea of the bearings was that instead of having a metal surface press against metal, the two metal surfaces would be separated by a thin film of oil, pumped into the space between the surfaces. Hodgkinson had calculated the power required to maintain a film in a bearing for the two-hundred-inch telescope, and had come up with six hundred horsepower. Motors that large would need a huge generating plant and would cause enough vibration to shake the entire mountain. Pease looked at Hodgkinson’s figures and gloated.

BOOK: The Perfect Machine
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