The Crossley was an awkward telescope to use, with a stiff mount that required a kick from time to time to get it to behave, but so many spiral nebulae could be photographed, or even seen visually with the telescope, that it raised disturbing cosmological questions. Heber Curtis’s continuation of this study provided the background for his contributions to the great debate in Washington.
Hale kept abreast of the work with the Crossley reflector at Lick. The incentive of following up on that work, and a program to extend the detailed spectrographic studies Hale had made of the sun to distant stars, was a compelling agenda for a big reflector. And when the headstrong young director of Yerkes Observatory got an idea in his head, there was no stopping him. Before the forty-inch refractor at the Yerkes Observatory was dedicated, Hale persuaded his father to contribute the funds to have a sixty-inch glass blank—the largest piece of glass the French foundries could mold in a single pour—cast for a giant reflector. William Hale made it clear that his gift was seed money; he would pay for the glass blank and nothing more. It would be up to George to find the money elsewhere to have mirror and other optical surfaces ground, to mount the telescope, and to build an observatory. George accepted the challenge.
The Saint-Gobain glassworks in France successfully poured the disk. It was annealed—heated, then gradually cooled over a period of months to avoid strains in the glass from rapid cooling—and shipped to Yerkes. Although funding to complete the project was nowhere in sight, Hale had a colleague at Yerkes, George W. Ritchey, begin grinding the mirror.
Ritchey had little academic training, but he had built several telescopes as a student at the University of Cincinnati, and in 1888 he set up a laboratory at home in Chicago before coming to work for Hale at the Kenwood Observatory. From Kenwood he moved on with Hale to Yerkes. Among astronomers Ritchey was known for his fierce concentration and what one colleague called “the temperament of an artist and a thousand prima donnas.” Ritchey would sometimes spend hours on a single photograph, setting and resetting the focus until it was exactly right, waiting for the perfect seeing conditions, then concentrating so intensely on guiding the fine motions of the telescope that an explosion nearby would not have distracted him. The resulting photograph would be an artistic masterpiece—except when Ritchey, lost in his concentration, neglected to record the date, time, or sky conditions, so that the plate was useless for scientific purposes.
Though hard on colleagues, Ritchey’s perfectionism was ideal in the optics laboratory. He was delighted to seal himself off for hours, even days, at a time, allowing no one near his project, ruling over his domain as an absolute tyrant while he patiently ground, then polished the disk.
While Ritchey began grinding the sixty-inch disk at Yerkes to the optical shape the future telescope would require, George Hale pounded the pavements again, making his pitch for funds to build the sixty-inch telescope. In 1901 he persuaded John D. Rockefeller to visit Yerkes Observatory. The usual show for VIPs was to mount an eyepiece on the telescope and point it to familiar objects for the entertainment and enlightenment of the visitor, but clouds covered the sky most of the day and evening of Rockefeller’s visit. Instead Hale took Rockefeller to the optical laboratory where Ritchey was working on the sixty-inch mirror. Ritchey showed off the procedures and tests used to figure and test a mirror. In one test Ritchey put his finger on the glass surface for a minute, then demonstrated that the distortion of the surface from the heat of his finger could actually be measured. Rockefeller was fascinated by the sensitivity of the test and asked to see it again. But interest wasn’t commitment, and Rockefeller wasn’t willing to fund Hale’s telescope. Nor, it appeared, was anyone else. Hale ran out of pavement to pound. The days of big telescope bequests seemed to be over.
Then, in 1902, Andrew Carnegie announced his gift of $10 million to establish the Carnegie Institution of Washington, “to encourage investigation, research and discovery in the broadest and most liberal manner, and the application of knowledge to the improvement of mankind.” Hale knew one member of the board of directors of the new institution, the legendary Elihu Root, secretary of war in Theodore Roosevelt’s cabinet. Root’s father, Oren Root, was a mathematician and astronomer at Hamilton College in upstate New York. Hale was convinced that Root had persuaded Carnegie to give the money.
He wasn’t entirely wrong. Carnegie’s original plan was to donate the money to a quasi-public body that would be under the authority of the president and Congress. President Theodore Roosevelt liked the idea. Nicholas Butler, the president of Columbia University, argued against it. At ten o’clock one night, when their discussions at the White House hit an impasse, Butler suggested that they call Elihu Root, famed for his cool intellect, to solicit his views. Root, openly grumpy about being telephoned so late, came over to the White House, read through the proposal and asked the president, “What damn fool suggested this idea?” With that Carnegie decided to establish an independent body, the Carnegie Institution, to administer his bequest. Root was a charter member of the board and later became vice chairman, then chairman.
Ever thorough, Hale prepared his pitch to the new organization by reading Carnegie’s writings. Carnegie had publicly expressed his admiration for Lick’s telescope bequest: “If any millionaire be interested in the ennobling study of astronomy—here is an example which could well be followed, for the progress made in astronomical instruments and appliances is so great and continuous that every few years a new telescope might judiciously be given to one of the observatories upon this continent, the last always being the largest and best, and certain to carry further and further the knowledge of the universe and our relation to it here upon earth.” To George Hale that sounded like an invitation.
Hale launched an appeal to Carnegie with a barrage of letters, photographs, recommendations from other astronomers, and exhibits of what a big reflector could do compared to even the large refractors at Lick and Yerkes. Edward Pickering, director of the Harvard College Observatory, who had been chosen to chair the Advisory Committee on Astronomy for the new Carnegie Institution, asked Hale to join the committee. Hale was thrilled at the invitation, but even a position as an insider didn’t help with his pet project. Like many philanthropists Carnegie preferred to initiate programs, rather than finish programs started by someone else.
The first substantial astronomy grant the Carnegie Institution made was to support J. W. Hussey of the Lick Observatory in an expedition to search for possible sites in the United States, Australia, or New Zealand for “a southern and solar observatory.” Hale’s own work was in solar astronomy, and when Hussey set off in 1903, Hale followed his reports of the excellent atmospheric conditions in Southern California. One site Hussey visited was a remote mountain rising above the desert roughly halfway between Los Angeles and San Diego. “Nothing prepares one for the surprise of Palomar,” Hussey wrote.
There it stands, a hanging garden above the arid lands. Springs of water burst out of the hillsides and cross the roads in rivulets. The road is through forests that a king might covet—oak and cedar and stately fir. A valley where the cattle stand knee deep in grass has on one side a line of hills as desolate as Nevada; on the other side majestic slopes of pines.
The observing conditions at a station some thirty miles southeast of Palomar were so bad that Hussey didn’t bother taking his telescope and measuring equipment to Palomar. The mountain had no regular stage or telephone and could be reached only by a road laid out with a 10 percent grade and some steeper portions; it was too remote for an observatory in 1903. But Hale would long remember the description, and Hussey’s raptures of the beauty of the spot and the clarity of the seeing. On the basis of Hussey’s reports, the Carnegie Institution chose Wilson’s Peak, close to Pasadena, as the site for a solar observatory and, Hale hoped, the sixty-inch telescope.
Even with a site selected for the future observatory, the partly ground sixty-inch mirror languished in the basement optics laboratory at Yerkes, waiting for money to
finish figuring the mirror and to build a mounting for a telescope. In 1904 the Carnegie Institution gave Hale $10,000 for Mount Wilson, and even that was only a token grant, barely enough to keep Hale’s hopes up. He paid $27,000 out of his own funds to keep the work going. It wasn’t until the marine biologist Alexander Agassiz decided not to accept a $65,000 per year grant for two years of research from Carnegie that Hale got a substantial grant for the sixty-inch telescope.
By then, the grinding of the disk had already gone as far as it could in the optical lab at Yerkes. The funds from the Carnegie Institution let Hale appoint Ritchey director of new optical and mechanical labs that were being constructed in Pasadena, close to what Hale hoped would be the site of the telescope on Mount Wilson. Hale himself moved to Pasadena to be near the project. In California he began a friendship with an attractive young woman named Alicia Mosgrove, who may have become his mistress. Hale was a discreet and private man. Evelina Hale, who later knew Miss Mosgrove, seems not to have known about George Hale’s relationship with her.
The optical laboratory in Pasadena was built with what were, for the time, unusual precautions. To keep dust off the grinding surfaces, the walls and ceiling were shellacked, and all air entering the room was filtered. During the final polishing operations the painted cement floor was kept wet, and a canvas screen was suspended over the mirror surface to protect it from airborne dust. Double windows and special heating equipment kept the shop and the disk at a steady temperature.
The sixty-inch glass disk was eight inches thick and weighed a ton. The turntable that held the blank was cushioned with two thicknesses of Brussels carpet, the looped threads serving as a spring mounting. For the first time carborundum was used as the abrasive to grind the glass. Carborundum, which had been invented in 1898 and first made at the Niagara Falls Elstree Works, was six times as effective at cutting as the emery powder it replaced, which reduced the time for rough grinding the shape of the sixty-inch disk from years to months. The quick-cutting abrasive also raised the price of an error. Ritchey’s reaction to that possibility was to become even more protective of his new lair than he had been in the optics lab at Yerkes. When the new optical lab was finally in operation, only Ritchey, dressed in a surgeon’s cap and gown, was allowed through the door.
Month after month he worked on the mirror, first grinding the disk to a rough spherical shape, then reshaping it to a parabola, and finally polishing the disk to the final optical surface. In spite of the extraordinary precautions, one morning in April 1907, while the mirror was being polished to its final figure, the surface was found covered with scratches. The cause was never discovered, but the scratches were serious enough that the mirror had to be reground, delaying the completion and putting new pressures on George Hale’s strained budget for the telescope.
It wasn’t just the mirror that raised the ante for the new project. The initial reports on the Mount Wilson site had been favorable. Hale hiked up the mountain himself to test the quality of the seeing, even climbed trees on top of the mountain with a small solar telescope, hoping the slight additional elevation would escape the effects of ground heat on the optics of the telescope. He scribbled notes that might be thought unusual for an astronomer:
Hay about 2c a lb. at top.
Grain about 2c a lb. at top.
Burros need about 100 lbs. a week of hay and grain together.
Burro cost about $25 with saddle, pack saddle, panniers, rope.
Basset & Son have 4 year lease of everything, road etc.
The conditions on the mountain were rough on men and equipment. Before a road adequate for tractors and dollies was finally built, components of the early solar telescopes and the heavy mounting for the sixty-inch telescope had to be carried up the narrow trail on the back of a donkey, mule, or man. On one early trip an unbroken burro rolled over with a valuable spectrograph prism on his back, destroying it. It was the price they paid for a good site.
It was 1908 before the sixty-inch telescope was ready. Ritchey had polished the great mirror for four years. The mountings, cast at the Union Iron Works, were almost lost in the San Francisco earthquake and fire. To reduce the friction on the bearings, the fork that held the telescope tube was mounted on a ten-foot-diameter float in a tank of mercury. The drive gears, marked off with a finely graduated circle fixed to the polar axis, had been ground to a precise shape and polished with jeweler’s rouge. To keep the mirrors of the telescope at a steady temperature, the dome was fitted with a canvas screen on a skeleton framework, and the mounting of the telescope was encased in blankets during the day. The shutters of the dome, fitted so they were almost airtight, were kept closed until shortly before sunset each evening. These precautions were dismissed as extreme by astronomers at eastern universities, until tests demonstrated that the mirror retained its figure during the temperature changes from day to night so well that it was optically as perfect at midnight at the site as when it had been tested in the temperature-controlled shop.
First light with the new telescope was in December 1908. To their delight the astronomers were able to obtain “perfectly round” star images of 1.03 seconds of arc—phenomenal resolution by comparison to other large telescopes. These images required exposures of eleven hours, during which the guiding mechanism of the telescope had to be corrected by hand. By 1910, with improved photographic emulsions, exposures of only four hours yielded images of stars of magnitude twenty—an improvement of several magnitudes over all previous telescopes.
As the work on Mount Wilson progressed, Hale resigned from Yerkes and was appointed director of the new Mount Wilson Observatories, a division of the Carnegie Institution of Washington. The new laboratories and offices on Santa Barbara Street in Pasadena were the most modern in the world. With the lure of the solar telescopes on the mountain and the new sixty-inch reflector, Hale assembled a talented cast of astronomers at Mount Wilson. But even the sixty-inch reflector on Mount Wilson—the biggest telescope in the world and the first to be built with a mounting and guidance system of the precision and temperature stability that long photographic and spectrographic exposures of distant, faint objects would require—wasn’t enough to satisfy George Hale.
4
The Whirligus
The competition for bigger and better machines was the spirit of the times. The years when Hale was guiding the construction of the forty-inch refractor at Yerkes, then the sixty-inch reflector at Mount Wilson, were the years of the great dreadnaught-building contest between Great Britain and Germany, an arms race as frightening to contemporaries as the nuclear arms race would be to a later generation. One country would launch a great battleship, then the other would counter with an even bigger battleship, extending the technology of armor, ballistics, and explosives until they provoked yet another generation of ships with larger displacements and more guns. Cartoonists and editorial writers goaded the competition, as the huge ships became symbols of national pride.
A parallel competition took place in architecture and technology. In France, Gustave Eiffel’s tower temporarily won the race for greater heights, but architects and developers in the United States were already dreaming of taller buildings. In Britain and the United States, Isambard Kingdom Brunel and John Roebling raced to build longer and taller bridges than the world had ever known. The Panama Canal, thought an impossible engineering feat after Ferdinand de Lessepss catastrophic failure, was nearing completion by American engineers, as important as a symbol of the triumph of American engineering as for military strategy and commerce of a nation with coastlines on two oceans. New York was building subways and massive aqueducts; the railroads were conquering mountain passes; aircraft engineers were building bigger and better flying machines.
George Hale had no competition in the telescope race, but each achievement of technology, each leap further into the cosmos that a big telescope provided, fueled the dream of reaching still further. Even before first light on the sixty-inch telescope, Hale approached a hardware merchant i
n Los Angeles, John D. Hooker, with the idea that he donate the money for the mirror of a still-larger telescope. Hale had bought hardware from Hooker’s company for the observatory, and he knew that investments in the oil industry had made Hooker a very wealthy man.
When George Hale called on Hooker in 1906, at his spacious two-story colonial home on West Adams Street, with its grand, wicker-furnished porches overlooking the gardens, Hooker had already lived in Los Angeles for twenty years, long enough to establish a reputation as a community leader and philanthropist. Still, he was flattered to be called on by a distinguished scientist; that same year Hale had been offered and had declined the presidency of MIT and a chance to become the secretary of the Smithsonian Institution. When the enthusiastic Hale described what an 84-inch telescope could do, and the attention that the astronomical discoveries it would make would draw to the telescope and its donor, Hooker asked how much the mirror would cost. Hale said $25,000. Within a few days Hooker pledged $45,000, on the condition that the new telescope that would bear his name be the largest in the world.
Though for different reasons, both the donor and the fund-raiser were convinced that bigger was better. To be sure that it wouldn’t be topped by any competitor, Hooker and Hale later agreed to increase the size of the proposed telescope to one hundred inches, a nice round number.
The trustees of the Carnegie Institution accepted the gift from Hooker with the understanding that they would not commit to mount the mirror—that if further funds were not found to build a telescope, the mirror, and the project, might languish. The order to pour the disk went out in September of 1906 to the Saint-Gobain glassworks, the only foundry that would even attempt to cast and anneal a one-hundred-inch-diameter glass blank.
The Perfect Machine Page 6