The year 2004 is Mount Wilson Observatory's 100th anniversary. Here is a series of articles about that first momentous year, 1904. They are reprinted from 2003-2004 MWOA publications and are written by Bob Eklund, MWOA Executive Editor:
I was recently talking to a man about how chilly this early winter weather seemed, and he said it took him a winter in Alaska to appreciate what we have here in Southern California. "You've been too long in paradise," he said.
Turn-of-the-century refugees from the icebound East usually spoke of winter as "The Season" in Southern California. One such man, Frederick H. Rindge, wrote in an 1898 book, Happy Days in Southern California, "What think you of taking a sleigh ride on Mount Lowe in the morning, descending on a marvelous inclined railway to Pasadena, where you stop long enough to gather your pockets full of oranges off the trees, and then electrically speeding away to Santa Monica for a swim in the Ocean of Peace—and all in the same day?"
It was just at this time of year in 1903 that Mount Wilson Observatory founder George Ellery Hale left his home in Williams Bay, Wisconsin, to begin a new life in Southern California and start building his dreamed-of observatory on Mount Wilson. Helen Wright describes the event in her biography of Hale, Explorer of the Universe: "On December 20, just six months after his first visit to the mountain, he arrived in Pasadena. The sky was a brilliant blue, the sun as warm as on a summer's day. On the station platform, he found his family waiting, dressed in summer clothes, startlingly different from the wintry garb they had worn when he had seen them off in Chicago."
Four days later, Hale wrote to his friend H.M. Goodwin, "Here I am sitting in the shade of the porch of our cottage with the sun too hot to stay in, the birds singing around me, and the flowers so numerous that I can't begin to tell their names. William is out in his cart, and Margaret has just run away to join him. Both are bare-headed and wear no jackets. I haven't been here long enough to be in the least blasé, and I can't say enough of the beauties of the place and the climate. The orange trees in the yards around us are full of fruit. One of them, so heavily loaded that it seems ready to break, is a great mass of oranges and roses, a great rose tree beside it thrusting up bunches of flowers in the midst of the fruit. I would give anything if you could be here to enjoy it all."
By the second week of January, Hale would begin the unprecedented task of creating the world's largest astronomical observatory on a remote mountaintop—but for now, he was content to enjoy the climate and revel in his new surroundings. As 1903 drew to a close, he and his wife Evelina spent their time touring the bustling, 17-year-old town of Pasadena, which then had 25,000 inhabitants and was reputed to be the wealthiest town of its size in the world.
Having moved his family from Williams Bay, Wisconsin, to Pasadena in December 1903, George Ellery Hale lost no time in acting on his plans for a new solar observatory on Mount Wilson. In the first week of January, he climbed the mountain, armed with a 3-inch telescope and accompanied by Seward Simons, a young boy of fourteen—and proceeded to set up the telescope near an old log cabin known as the Casino.
Hale biographer Helen Wright later interviewed Seward Simons and describes the events of that memorable trip in her book, Explorer of the Universe: "From the beginning he [Hale] treated the boy as an equal, even asking his opinion on astronomical questions. In retrospect Seward concluded that Hale was 'the most vivid character, the most interesting personality I have ever known.'
"Seward's most graphic memory, however, was of that first expedition when Hale was making observations of the sun at various heights above the ground. Before he knew it he was scaling a yellow pine, dragging the telescope with him. In his diary Hale recorded his observations. At 10:55 A.M., with clouds forming to the west and south, he noted: 'Definition poor at tree…Tested seeing in Tree at 32 feet and 68 feet above ground. Apparently some improvement, but found to be better at ground just afterwards. Tree meas. 80 feet.' Perhaps he already realized the possibilities of a telescope raised high above the ground where heat waves would not distort the sun's image.
"That first night they stayed in the Casino. Through a gaping hole in the roof they could look up at the shimmering stars. For a while they talked; then, worn out by the day's activities, they slept—to dream perhaps that the 60-inch telescope was mounted and the Mount Wilson Solar Observatory a reality."
On February 3, 1904, Mount Wilson Observatory founder George Ellery Hale had lunch in downtown Los Angeles with a man who was to become a key factor in the future success of Mount Wilson Observatory: John D. Hooker. Hooker had made a fortune in the hardware and steel-pipe business, but he was also interested in astronomy and had a telescope in the garden of his elegant West Adams Street mansion in Los Angeles. Shortly after that first meeting, Hale called on Hooker at home and, before the day was over, had persuaded him to pay the cost of bringing Yerkes staff astronomer E.E. Barnard and his Bruce 10-inch photographic telescope to Mount Wilson.
The winter of 1903-04 was a relatively dry one in Southern California, with a total of 8.72 inches recorded for that season in Los Angeles. At Mount Wilson, there was no major snow until March. After Hale's expedition to the mountain in the first week of January, it appears that he remained busy in the city and did not return to Mount Wilson until February 29 (1904 was also a Leap Year).
As chronicled by Hale biographer Helen Wright in her book Explorer of the Universe: "…on February 29, Hale climbed Mount Wilson with a carpenter named Britton. They spent the night in the 'Casino.' 'Plenty warm enough but some drafts.' In the morning they set to work on repairs that would make the cabin usable as a shelter until a more permanent structure could be built. That afternoon Hale started down the trail. On the way he 'shot the slides' that were cut through the heavy covering of chaparral as shortcuts between zigzags of the trail. He arrived at the foot of the trail covered with dust. There he picked up his bicycle and rode it back to Pasadena.
"That evening he donned his frock coat to speak on the work of an astronomer at the home of Mrs. Burdette, the 'cultural leader' of the community. The following day, he again climbed the mountain, this time with George Jones … who was to become as legendary as Paul Bunyon for his feats on the mountain." More on George Jones in our March newsletter!
On March 2, 1904, after having just hiked down from Mount Wilson the day before, George Ellery Hale again hiked to the mountaintop, accompanied this time by George Jones. In her Hale biography, Explorer of the Universe, Helen Wright describes Jones as "a genial stonemason and an enormously powerful man who was to become as legendary as Paul Bunyon for his feats on the mountain."
Wright continues: "To Jones the huge granite blocks on the peak seemed like mere pebbles. He picked them up with complete nonchalance while Hale looked on in amazement. It soon appeared that he could do almost anything with his hands, and was remarkably skillful as a designer." [NOTE: George Jones was the great-uncle of Gene Burt, late husband of MWOA Board of Trustees member Shirley Burt.]
"With such expert help, the wrecked log cabin [called the "Casino"] was rebuilt. By the time the first heavy storm struck, it was not only habitable but cozy. 'When real winter descended with its furious blasts of snow,' the huge fireplace, able to hold logs two feet in diameter, saved their lives. It even had an embryonic library containing Agnes Clerke's History of Astronomy, her Problems in Astrophysics, and a volume of D'Annunzio's poems."
Later in March, Hale was joined by Ferdinand Ellerman, who had been a key member of Hale's staff at Yerkes Observatory in Wisconsin and was to become one of his most valued associates at Mount Wilson.
Again quoting Helen Wright: "He arrived on a day somewhat different from what he had been led to expect in 'sunny' California. Hale met him at the foot of the trail. On the way up the mountain they ran first into clouds, then into rain, and finally, above Martin's Camp, into a heavy snowstorm. That night the thermometer dropped to 17 degrees. The next morning it was 26 degrees in the Casino, with an inch and a half of snow on the ground and ice glittering on trees and bushes. Yet Ellerman was as elated to be there as Hale was to have him. With his skill in instrument design and his ingenuity in making equipment out of available materials, however meager, he entered wholeheartedly into the busy, hectic days on the mountain. He entered so much into the spirit of the place, in fact, that, as Hale observed, he soon looked as if he had always lived there. When [Walter P.] Adams arrived some months later, this, as he was to describe it afterward, was the Ellerman he found: 'He wore a ten gallon hat, high mountain boots, and a full cartridge belt from which hung a revolver on one side and a hunting knife on the other.' He commented, 'I was greatly impressed and pictured a struggle for existence on the wild mountain top, which bore little resemblance to later actuality.' "
Once the "Casino" cabin on Mount Wilson had been made livable, George Ellery Hale and Ferdinand Ellerman, his first staff astronomer at the mountain observatory-to-be, were ready to undertake their first Mount Wilson endeavor in solar astronomy. A horizontal solar telescope with a 12-inch flat coelostat mirror, which had originally been used on the Yerkes expedition to the 1900 eclipse in Wadesboro, N.C., was set up in an open area just east of the Casino (roughly where the upper parking lot is today).
By April 10, 1904, this instrument was ready for trial. Following is Hale's description of what happened, as quoted by Hale biographer Helen Wright in Explorer of the Universe:
"The sun rose resplendently in a cloudless sky, and its image as first seen on our focussing screen was sharply defined. We prepared to make photographs, but before we could get the first exposure, the image had become blurred and indistinct. I had feared asymmetrical heating of the 60-foot tube of building paper by the sun and had spread canvas before it as a shield. But this was not enough, and a radical change was obviously needed. Ellerman and I were alone on the mountain and must do the work without delay, as I had booked to leave for the National Academy in Washington two days later. So we attacked the tube, ripped off all its upper faces, dismounted the canvas and stretched it up as a flat shield toward the east, no longer enclosing the heated air. By nightfall, we were ready. Visitors to the mountain, when asked in Pasadena next day what they had seen, said, 'two men working like devils.' "
Continuing in Helen Wright's words: "Early the next morning the 'devils' plunged into work. It was clear and calm, 'a day typical of the long Mt. Wilson dry season.' The sun's image was sharp, the sharpness held, and it continued to hold as a result of their feverish work the previous day. They took eight photographs at different foci, and developed them. The results were superb. Immediately, then, Hale started down the mountain, leaving Ellerman to wash and dry the plates. The next morning, he left for Washington, carrying his latest results—on his way, too, to receive the Draper Medal from the National Academy of Sciences." [Editor's Note: Five months earlier, on November 18, 1903, the National Academy of Sciences had visited Hale's newly completed Snow telescope at Yerkes Observatory.]
"In Chicago he learned that Miss Helen Snow, the donor of the telescope, had withdrawn her objection to the temporary removal to California of the Snow horizontal telescope for studying the sun. This good news was offset by [donor Charles T.] Yerkes's refusal of further support for salaries at Yerkes. Nevertheless Hale was elated. That night he talked until long past midnight with his brother on his hopes and dreams for Mount Wilson. The following morning Will Hale, who was now a lawyer in Chicago, announced that, after consultation with Uncle George, they had decided to invest some capital in the 'solar plant' on that mountain. He called George the greatest gambler in the world, but trusted that everything would come out well in the end. George, who for the last three months had been gambling on the venture and pouring every cent he owned into it, and borrowing on top of that, was jubilant."
Hale continued on to Washington, D.C., arriving there on April 16. He was met there by Dr. John Billings, Chairman of Carnegie Institution of Washington's Board of Trustees, and Mrs. Henry Draper, wealthy widow of the noted pioneer astrophotographer and spectroscopist Henry Draper. Watch for more on this trip, and its propitious results for the future Mount Wilson Observatory, in our next issue.
In Washington, D.C., to receive the Draper Award from the National Academy of Sciences, Hale was able to secure a $10,000 grant from the Carnegie Institution of Washington (C.I.W.) to move the Snow telescope from Wisconsin to California—with the promise that at least $30,000 would be granted in December to support the Yerkes expedition to Mount Wilson (as it turned out, the amount granted by C.I.W. to Mount Wilson in December was $300,000, not $30,000). Hale now proceeded to Chicago, to negotiate with President Harper of the University of Chicago (Yerkes’ parent organization) and come to terms on his—and Mount Wilson’s—future status.
In the Hale biography Explorer of the Universe, Helen Wright notes that the Yerkes “expedition” to Mount Wilson for solar research was officially organized under the joint auspices of the University of Chicago and the C.I.W., with the understanding that the funds granted by the C.I.W. would be used for the construction of piers and buildings and other expenses, while the University of Chicago would furnish the instrumental equipment and pay the salaries of some of the members of the party.
In Helen Wright’s words, “With this agreement settled, with the university paying the salaries of Hale and Ellerman, with [George] Ritchey’s salary paid out of Carnegie funds, with Hale paying Adams’s salary himself, and the rest of the Yerkes staff provided for, Hale left Chicago in a joyful mood on the ‘Yerkes Expedition.’ He was joined by Ritchey and by Adams, who, in his vivid account of the ‘Early Days on Mount Wilson,’ describes their journey across the country. He tells of Hale’s excitement when, toward the journey’s end, he realizes that ‘the decision had been made and that a new life with new responsibilities and opportunities lay before us all.’ ”
Arriving back in California from Washington and Chicago in early June 1904, George Ellery Hale made it his first order of business to meet with the directors of the Mount Wilson Toll Road Company (owners of the land atop Mount Wilson) to discuss securing a lease for the proposed Observatory.
In the words of Helen Wright, author of the Hale biography Explorer of the Universe: "On June 13, 1904, the lease was signed — in the name of George Hale; it was for ninety-nine years, free of rent. Privacy was assured — the land at the east end of the mountain was some distance from the trail's end and from any point where an electric railroad might reach the summit.
"After this, one of the first tasks was the choice of a site for living quarters. Years before, Hale had become fascinated by Curzon’s tale about the monasteries of the Levant, perched on rocky promontories, looking out on distant peaks. He had dreamed of building such a monastery, where the male astronomers could live while observing on the mountain. (He had not forgotten the difficulties at Yerkes, or his resolve made then that, if he should ever found another observatory, the astronomers and their families would not live on the observatory grounds.)
"Soon after their arrival, therefore, he set out with Adams in search of a 'monastery' site. To explore the ridge they had to hack their way with small hatchets through the dense underbrush. Finally, about a quarter of a mile away, at the end of the ridge, they came out on a small opening. The ground was nearly level; on three sides the land fell away in sheer precipices, revealing a magnificent view of valleys, canyons, and distant peaks. 'This is where we must build it,' Hale exclaimed. So the future 'Monastery' was born.
"Six months later, designed by [the celebrated Southern California architect] Myron Hunt, it was finished. It had a large living room and a huge fireplace built of granite from the mountain. On a beautiful, mild still night in December, Hale, Adams, and Ellerman moved from the old Casino. They walked down the hill carrying lighted candles, and that night, sitting late around the embers of a fire, they talked of their hopes for a great observatory."
The major activities on Mount Wilson during the summer of 1904 were the building of the "Monastery" residence hall and the moving of the Snow Horizontal Solar Telescope from Yerkes Observatory. While these activities were progressing under the guidance of George Ellery Hale and two of his former Yerkes staff astronomers, Walter Adams and Ferdinand Ellerman, visitors began to arrive, as Helen Wright describes in her Hale biography Explorer of the Universe:
"Meanwhile news of the activity on the mountain had spread—over the United States, even to Europe. Before the Monastery was finished a flood of visitors had arrived. One of the first to come was the genial English astronomer H. H. Turner, with his wife. The only available accommodation was the powerhouse, a small wooden building. There they took up residence. They insisted that they enjoyed themselves 'hugely' in the company of the gas engine. Nearly fifty years later Daisy Turner was to write, 'We both adored that whole experience, and though Herbert had always been fond of Prof. Hale it sealed our friendship forever; and I have always felt proud to share the friendship of such a truly great (and most lovable) man.'
"Soon after the Turners, Harry Goodwin and Arthur Noyes, Hale's old college friends, arrived. They stayed on until he had to leave for the East. Often then they talked again of working together, if possible in California. But many years were to pass before their hopes were to be realized even in part with the arrival of Noyes in Pasadena."
Walter S. Adams, George Ellery Hale’s close associate and Director of Mount Wilson Observatory after Hale’s retirement, throws additional light on Summer 1904 activities at the mountain in his Biographical Memoir of Hale, which he presented to the National Academy of Sciences at their Autumn Meeting in 1939 (a year after a Hale’s death). The following is from this memoir, published by the Academy in 1940:
It was a period of intense physical and mental activity for Hale, and one that he enjoyed beyond measure. The quiet and isolation of the mountain top appealed to him enormously and in the thousand details of planning and construction under pioneering conditions he found an interesting opportunity to apply his resourcefulness and inventive skill. He designed a special small horse-drawn truck, steered from either end, for transporting the heavier parts of the Snow telescope up the narrow foot-trail two feet in width; he planned the living-quarters for the staff, the first “Monastery,” on a site selected after a strenuous afternoon devoted to cutting trails through the thick brush; he studied the water supply and means for developing it; but most of all he investigated in great detail methods for improving the definition of the sun’s image, especially some hours after sunrise when radiation from the heated ground became more injurious. Tests of the “seeing” at different elevations above the ground in the neighborhood of the beam incident upon the telescope, stirring with fans of the air traversed by the beam from the coelostat mirrors, and artificial heating of the backs of the coelostat mirrors to compensate for the distortion produced on their front surfaces by the sun’s heat—all of these matters were studied with great care by Hale, and the conclusions were incorporated in the design of the building for the Snow telescope, and in later years into the design of the 60-foot and 150-foot tower telescopes. Although he felt a deep sense of responsibility at this time for the successful outcome of this development work as affecting the future recommendations of the Carnegie Institution, he always retained his hopefulness and courage and faced all his problems with a joyous lightheartedness which was a constant delight to his associates. The small group on Mount Wilson had been increased by the addition of [E.E.] Barnard who had brought the Bruce photographic telescope from the Yerkes Observatory to photograph the southern Milky Way, and the gatherings around the fireplace at the Monastery on the stormy evenings of the winter of 1904-5 with Hale present form one of the choicest memories of these early years of the history of Mount Wilson.
Throughout the summer and fall of 1904, two major projects were in progress on the summit of Mount Wilson: the construction of the Snow Horizontal Solar Telescope, and the building of the astronomers’ residence facility. This required the bringing of massive amounts of material up the narrow Mount Wilson toll road—little more than a trail—from Altadena, as is described in the following, written by Mike Simmons for a 1983 issue of Reflections and based on Walter P. Adams’ article in Publications of the Astronomical Society of the Pacific, Vol. 59, No. 350, “Early Days on Mount Wilson:”
“Transported to Mount Wilson by mules and horses in 60 separate trips from Pasadena, the Snow telescope became the world's first permanently mounted solar telescope. Many of the pieces were carried on the backs of the animals, but for the heavier loads a special carriage was designed. Its front wheels were steered by a man riding on the carriage, while, in order to negotiate the sharp turns, the rear wheels were guided by a tiller operated by a man walking behind the contraption. The narrowness of the trail limited the width of the bed to 24 inches. With this device and two horses, 1,000-pound loads could be transported to the mountain. The sight of this entourage on the trail—men, animals and machine—always figures prominently in the recollections of those on the mountain at this time.
“The mode of transportation figured in the design of the telescope's housing, for no structural element of the Snow building (with the exception of one ten-foot steel rod) is more than eight feet long. Similarly, the doors of the original ‘Monastery’, the astronomer's living quarters (which burned in 1909), were made very narrow to keep them from dragging on the ground while being hauled up to the mountaintop on the animals' backs. Nevertheless, several arrived with rounded corners.”
With this construction on the mountain proceeding well, Hale felt he could leave this work in the capable hands of Adams and Ellerman while he took a trip east. Helen Wright takes up the narrative at this point in her Hale biography, Explorer of the Universe:
“On September 12th, Hale left for Washington. On the way he stopped in St. Louis for the scientific congress that was being held in connection with the great exposition there. He was chairman of the astrophysical section and chief sponsor of plans for the ‘International Union for Cooperation in Solar Research’—under the significant auspices of the National Academy of Sciences…
“On September 23, 1904, he called the meeting to order in the Hall of Congresses that had been provided by the far-seeing organizers of the St. Louis Fair. He was acting as Chairman of the Committee on Solar Research of the National Academy of Sciences, which, at his request, had approved his plans and issued the call for the conference. His opening address was eloquent. He pointed out that with new instruments and methods, the possibilities of solar research had barely been tapped. He described the importance of laboratory spectroscopy and stressed the need for applying spectroscopic methods to the problems of solar physics…”
Hale left that same night for Chicago, to stay a few days with his uncle there before proceeding on to New York and Washington to lobby with the Carnegie Institution of Washington for funding for the new Mount Wilson Solar Observatory. (More on this part of the trip in our next issue.)
Mount Wilson Observatory founder George Ellery Hale spent most of the month
of October, 1904, in New York City and Washington, D.C., talking to
officials of the Carnegie Institution of Washington about funding for the
Mount Wilson Observatory.
Encouraged by the news that naturalist Alexander Agassiz had recently turned
down a large Carnegie grant, freeing up some $65,000 a year, Hale decided to
present two alternative funding proposals to the Carnegie Executive
Committee, which was meeting in Washington, D.C. One plan would only pay
for minimal operations with the Snow telescope; the second, and larger, plan
would also cover the creation of a stellar reflecting telescope using the
60-inch mirror given to him by his father (which was still waiting in the
basement of Yerkes Observatory).
Continuing in the words of Hale biographer Helen Wright:
"Before the [Carnegie Institution Executive] committee, which was meeting at
the New Willard Hotel, Hale spoke first of the smaller plan, which required
the $30,000 practically promised by the trustees at their April meeting. He
knew, of course, that this amount would just about cover what he personally
had already spent on Mount Wilson. Then he turned to the 'big scheme.'
Thinking of the Agassiz grant, he noted that this plan could be financed by
a grant of $65,000 a year for five years. The committee members questioned
him in detail, and again he described all that could be accomplished if only
the 60-inch could be mounted. Afterward he wrote to [his long-time friend
Harry] Goodwin, 'I am not sorry I mentioned the larger plan. They seemed to
take interest in it, and asked me many questions. There was not a
suggestion of criticism for spending the $27,000 in advance of the
appropriation.' Prospects for success, he felt, were great.
"Later, [Executive Committee Secretary Charles] Walcott telephoned to say
that the committee was favorably inclined to give him enough for the 'plant'
($225,000 at least) in three years instead of five, plus running expenses.
Afterwards there would probably be $40,000 a year for at least ten years.
In two weeks the committee would decide definitely what recommendation to
make to the trustees. Hale, elated, told Goodwin, 'It certainly looks as
though it had been worth while to stay over.'
"It was late in October, 1904, when Hale arrived back in Pasadena. After
these harrowing weeks he was delighted to be home and at work on the
mountain. There he anxiously awaited the decision of the Executive
Committee."
Continuing our story of George Ellery Hale's efforts in 1904 to obtain
funding for his hoped--for Observatory, we quote from Helen Wright's Explorer
of the Universe:
"It was late in October, 1904, when Hale arrived back in Pasadena. After
these harrowing weeks he was delighted to be home and at work on the
mountain. There he anxiously awaited the decision of the [Carnegie
Institution of Washington] Executive Committee. On November 2nd, it came.
Relaying the news to his brother, Will, he wrote, '[Committee Secretary
Charles D.] Walcott just telegraphed that the Executive Committee will
recommend a grant of $150,000 for the Solar Observatory for next year. This
would be followed by the same amount the second year. Don't say anything
about this now, as it must be confirmed by the Trustees in December.'
"This time Hale was sure the recommendation would be accepted by the
Trustees. He was surprised, therefore, when his more cautious brother wrote
back, 'Your telegram from Walcott is very interesting. But I do not regard
it in as sanguine a light as you do. For my part, I think the chance that
the Trustees will confirm this are just about even. The Trustees have been
known to turn down the Executive Committee very hard.'
"When at this point George proposed buying a house in Pasadena, Will was
appalled. He could not understand his headstrong, impulsive brother. He
was willing to do anything within reason to push George's observatory plans,
but he could not see his way to gambling further on an uncertain future.
'You can't afford to load up with a house and lot at present,' he exclaimed,
then added: 'Dr. Isham is not altogether wrong when he says you are the
biggest gambler he knows. The answer is that sometimes it is necessary to
gamble. But the present proposition looks to me really to be a speculation
in land.' Still, despite his doubts, he concluded, 'I would regard a loan
to you as perfectly safe, of course; and will ask Martha's consent if you
desire.'"
However, the cost of a Pasadena house was small compared to what Hale had
already gambled on his Mount Wilson adventure. Now, as California's Indian
summer gave way to November chill, construction crews on the mountain
continued to move toward completion of the reincarnated Snow Solar Telescope
and the astronomers' residence hall that has ever since been known as "the
Monastery"--all paid for with some $27,000 that Hale had advanced from his
personal funds without any certainty of Carnegie funding. The consummate
gambler was now poised to win or lose everything, depending on the decision
of Carnegie's Board of Trustees when it met in December.
On December 13, 1904, the Board of Trustees of the Carnegie Institution of Washington met to consider Hale's proposal to establish a solar observatory on Mount Wilson. Some of the trustees objected to including a substantial amount in the appropriation for new instrumentation. Charles Hutchinson of Chicago, usually one of Hale's most ardent supporters, was especially hesitant. "I would not commit myself to $40,000 a year for equipment," he declared, "because if he has it, he is pretty sure to spend it, and if he has not that much he will probably get along on less." Finally, however, a motion was passed to appropriate $310,000—subject, however, to approval by Carnegie's Executive Committee, which was to meet the following week.
We continue in the words of Helen Wright's Explorer of the Universe. "Somehow, that week passed. On December 20th, the day of the momentous Executive Committee meeting, Hale was on his way up to the mountain, riding a mule. He had reached Martin's Camp. There, unexpectedly, he was called to the old single-wire telephone. The operator said she had a telegram from Washington. Hale, trembling in spite of himself, asked her to read it. From her voice, which was difficult to hear, he gathered the wonderful news that the Executive Committee had appropriated $150,000 a year for two years and had authorized the immediate execution of the larger plan!
"Now, at long last, after endless months of uncertainty, Hale knew, and soon all the world would know, that the Mount Wilson Solar Observatory was a reality. At thirty-six Hale was director of the second great observatory he had founded—one that, when it was completed, would be the largest in the world.
"On that memorable day, December 20, 1904 (the actual date of the founding of the observatory), the new Carnegie president, the noted mathematical physicist Robert S. Woodward (who had been chosen to succeed Gilman), sent Hale the official notice of the grant. He wrote, 'I beg to assure you of my warm interest in the great enterprise you have undertaken, and also to assure you that it will be my earnest endeavor to cooperate with you in all the work that may come in the years that are before you.'
"It was a year to the day since Hale had arrived in California with the Yerkes expedition. Now Walcott sent a check for $30,000, the first installment on the larger sum, which would barely cover the amount Hale had borrowed to keep the project going!"
We now continue our focus on Mount Wilson's history. But instead of looking only at 1904, we'll survey a selection of things that happened at Mount Wilson month-by-month through the entire past century. New items will be added continually.
The ranch referred to here is Lake Vineyard, the San Marino home of Benjamin "Don Benito" Wilson, where Brewer and his colleagues were camped. In just three years, Don Benito would build a trail to the summit of the mountain that bears his name.
The following account is in Brewer's own words:
"It was long after dark when we got back. A hearty supper so much refreshed me that I spent the evening, New Year's Eve, at Mr. Wilson's, and spent it very pleasantly. He has a large family; there are several ladies there.
"Tuesday (New Year's), we sent the wagon to town (Los Angeles), nine miles distant, for supplies. Professor Whitney and I, along with Mr. Wilson, rode a few miles to visit some old quarries and see some other things of interest. It was a lovely day. We dined at five at Mr. Wilson's—a most sumptuous dinner. A small party was there and we spent a pleasant and lively evening, notwithstanding that our "rig," just from camp, was hardly fashionable. The evening was lovely, as was the last. The midnight bells at the old Mission the night before, tolling out the old year and in the new, were sweet, but no sweeter than the nine o'clock bells of that New Year's night."
From Up and Down California in 1860–1864, edited by Francis P. Farquhar, published 1966 and 1974 by the University of California Press.
January 18, 1876 — Mount Wilson astronomer Arthur S. King is born.
January 14, 1881 — Mount Wilson astronomer Francis G. Pease is born.
January 24, 1882 — Mount Wilson astronomr Harold D. Babcock is born.
January, 1904 — Having come to California from Wisconsin the month before, George Ellery Hale begins his work at Mount Wilson, in the first week of January, 1904, taking a small telescope up to the mountain to test the quality of solar images. He climbs a pine tree and finds that, as expected, the image above ground is considerably better than at ground level.
January 13, 1909 — Mount Wilson astronomer Olin C. Wilson is born.
January 2, 1914 — Work begins on the widening of the Mount Wilson Toll Road to accommodate the transportation of 100-inch telescope components. The last major component, the mirror, made the trip to the mountaintop in July, 1917.
January 4, 1917 — Daily sunspot drawings in 150-foot tower begin (continued until September 16, 2004).
January 19, 1919 — Milton Humason, who later gained fame as Edwin Hubble's assistant in the research that led to Hubble's confirmation of the expansion of the Universe, kills a mountain lion on this date. In Mount Wilson Observatory's early days, Humason was first a mule-driver, then the Observtory's janitor, before he became a night assistant and photographer on the 60-inch and 100-inch telescopes.
January 1, 1925 — A historic paper by Edwin Hubble, is delivered at the American Astronomical Society meeitng December 30, 1924 - January 1, 1925, shows the distance to M31 (the Andromeda Galaxy) to be vastly larger than was previously believed, proving that our Milky Way is only one of many galaxies.
January 29, 1931 — Albert Einstein visits Mount Wilson Observatory. (According to Helen Wright, Einstein also visited the Hale Solar Laboratory in January, 1930.)
January 23, 1943 — U.S. 24-hour rainfall record of 26.12 inches set at Hoegee's Camp (just southeast of Mount Wilson).
January 5, 1989 — Carnegie Institution of Washington turns over management of Mount Wilson Observatory to the Mount Wilson Institute (MWI), a non-profit California Corporation.
February 1891 — Pasadena contractor Thomas Banbury and his crew of 25 men began work building the Mount Wilson Toll Road (then just a trail wide enough for a horse and rider), starting near the mouth of Eaton Canyon. By June the 10-mile pathway, much less steep and easier to negotiate than the 8-mile Sierra Madre trail, was in usable shape, in spite of a grizzly bear and her cub who reportedly lived just above Henninger Flats and terrorized the workmen on several occasions. The new trail was officially opened to the public in July, and the toll fixed by the Los Angeles County Board of Supervisors at 25¢ for hikers and 50¢ for riders on horse or mule. The trail was widened to six feet two years later to better accommodate two-way stock travel. (From The Mount Wilson Story, by John W. Robinson.)
February 29, 1904 — George Ellery Hale climbed Mount Wilson with a carpenter, spent the night in the drafty "Casino," spent the next day repairing that ancient cabin, jogged down the trail to Pasadena (sliding down dusty shortcuts that cut across the zigzags of the trail), picked up his bicycle at the bottom of the trail, rode it home covered with dust, and gave a talk that same evening on the work of an astronomer at the home of a Mrs. Burdette, the "cultural leader" of the community. Just a typical day for Hale!
February 15, 1935 — The aluminizing bell jar for the 100-inch telescope arrived by way of the new Angeles Crest highway (which was officially opened to the public two months later, on April 19). The 100-inch was aluminized for the first time on February 27.
February 26, 1986 — Mount Wilson Institute (MWI) was incorporated, with Arthur Vaughan serving as its first director.
March 1, 1887 — Edward Charles Pickering, director of Harvard College Observatory, announced to the astronomical world that his institution had been granted a very substantial sum of money, the Boyden Fund, for the purpose of establishing a mountaintop astronomical observatory. Uriah Atherton Boyden, born in 1804, invented and designed water-powered turbines and water-wheels that helped to power 19th-century manufacturing and brought him a fortune. Most of this (more than $230,000) was presented to Harvard College Observatory. The initial result of this was the creation of the 13-inch Boyden telescope, made by Alvan Clark & Sons and placed on Mount Wilson in 1889.
March 24, 1893 — Mount Wilson astronomer Walter A. Baade is born.
March 9, 1894 — Edison R. Hoge is born (see article in March 2005 Reflections in Publications page).
March 1906 — Week-long rainstorms were not unknown to George Ellery Hale, and apparently he exulted in the wild weather. In Explorer of the Universe, Helen Wright quotes Hale's March 1906 letter to his friend R.J. Wallace at Yerkes Observatory: "We have just gone through a little 'shower' on the mountain, which lasted from Sunday morning until Saturday noon. During a portion of this I plunged my way through raging mountain streams and rain which came down in chunks, carrying a pack weighing several pounds, more or less, on my back. When I arrived at the summit, the only part of me that was dry was my throat, and I had some good old Scotch to wet it, so I did not suffer any. We had something over 15 inches of rain during this 'shower.'"
Always fond of poetry, Hale would sometimes recite passages to his friends from his favorite poets, Keats and Shelley. And at least once, probably on a stormy night at Mount Wilson, he composed these lines of his own, which were found penciled in his familiar script on a yellow pad at the Hale Solar Lab:
"What joy to know the swirl of snow
The howling of the gale!
What sport to hear, twixt joy and fear
The thunder and the hail,
For they're without, when storm-gods shout
And grapple in the gloom,
While here beside the hearthstone wide
The flames dance through the room…"
March 17, 1910 — Andrew Carnegie visits Mount Wilson.
March 1925 — Hale Solar Laboratory in Pasadena is completed.
March 15, 1929 — Edwin P. Hubble confirms the expansion of the Universe.
A small observatory building of wood and canvas would be constructed on the southwest edge of the mountain-top, a spot known afterwards as Harvard Observatory Point. In May, 1889, the Harvard astronomers begin their work, photographing more than 1,150 stars over the course of a year and completing a map of the heavens that included "many objects of the celestial world never heretofore viewed by mortal man."
April 7, 1892 — Harvard University President Charles W. Elliot visits Mount Wilson. A nearby peak is officially named Mount Harvard in honor of his institution, the first to bring astronomy to Mount Wilson (but for only 18 months).
April 11, 1904 — First solar images are made at Mount Wilson. Once the "Casino" cabin on Mount Wilson had been made livable, George Ellery Hale and Ferdinand Ellerman, his first staff astronomer at the mountain observatory-to-be, were ready to undertake their first Mount Wilson endeavor in solar astronomy. A horizontal solar telescope with a 12-inch flat coelostat mirror, which had originally been used on the Yerkes expedition to the 1900 eclipse in Wadesboro, N.C., was set up in an open area just east of the Casino (roughly where the upper parking lot is today). By April 10, this instrument was ready for trial, and the following day Hale and Ellerman took eight superb photographs of the sun in perfect seeing conditions. Leaving the next day for the East, Hale took these solar images with him, and in his subsequent meetings with Carnegie officials they served as valuable proof of the imaging capabilities at Mount Wilson.
April 5, 1926 — 0.65 inches of rain falls in one minute near the summit of Mount Wilson, a world record for rainfall in a single minute that stood for 30 years.
April 19, 1935 — The paved highway from Red Box Junction to Mount Wilson is officially opened to the public. Thus from this date forward, the public is able to access Mount Wilson via the high-speed Angeles Crest Highway, without having to negotiate the old toll road.
April 7, 1995 — Georgia State University selects Mount Wilson as the site for its CHARA (Center of High Angular Resolution Astronomy) Array.
May 11, 1889 — Mount Wilson’s first astronomical photograph is taken with Harvard College Observatory’s 13-inch telescope, which was set up near the site of the present-day pavilion. The two Harvard observers, Robert Black and Edward King, began their work, which included photographing stars, the moon, Mars, Jupiter, and the Orion nebula. The two men lived in a shelter adjacent to the telescope, and boarded with A.G. Strain, owner of Strain’s Camp. In November, King returned to Cambridge, leaving Black to operate the telescope with the assistance of the teen-age son of Arthur N. Carter, mountaineer and prominent Sierra Madre citizen.
May 1904 — On a visit to Washington, D.C., George Ellery Hale convinces Carnegie Institution of Washington’s Board of Directors to advance the sum of $10,000 to move the Snow solar telescope from Yerkes Observatory in Wisconsin to Mount Wilson, with the promise of an additional $30,000 in December. As it turned out, the amount granted to Mount Wilson in December was $300,000, not $30,000.
May 28, 1907 — The first car (a 1907 Franklin) reaches the summit of Mount Wilson, driving up the toll road from Altadena.
May 20, 1912 — Fore River Shipyards in Massachusetts (where the main line of work was building battleships) begins work on the tube and mount for the 100-inch telescope.
May 11, 1914 — Hale writes a letter to Henry E. Huntington proposing a plan for the preservation and use of Huntington’s books and paintings (this was the genesis of the Huntington Library).
May 10, 1948 — The Palomar 200-inch telescope is dedicated as the "Hale Telescope."
May 24, 1982 — The Mount Wilson Observatory Association (MWOA) is incorporated as a Non-Profit California Corporation.
May 2002 — Mount Wilson’s Meade 16-inch Schmidt-Cassegrain telescope goes into operation.
May 2004 — The historic Hale Solar Laboratory in Pasadena, built by Hale in 1925 to be his personal observatory, is acquired by the noted Los Angeles architects Elizabeth Moule and Stefanos Polyzoides.
June 25, 1903 — Hale visits Mount Wilson for the first time, and makes the decision to locate his new observatory at this site.
June 13, 1904 — Hale signs a 99-year lease for the Observatory property (free of rent) with its owner, the Mount Wilson Toll Road Co.
June 25, 1908 — Using the newly-built 60-foot solar tower telescope, Hale detects the magnetic field associated with a sunspot. This is the first detection of a magnetic field anywhere outside the Earth.
June 8, 1918 — Mount Wilson astronomer Alfred Joy discovers Nova Aquilae.
June 6, 1938 — Mount Wilson astronomer Seth Nicholson discovers the 10th satellite of Jupiter with the 100-inch telescope (he discovered four Jovian satellites in all, three of them at Mount Wilson).
June 18, 1941 — Mount Wilson astronomer Walter A. Baade discovers the remnant of Kepler’s 1604 supernova.
June 6, 1967 — Metromedia Corp. opens Skyline Park (complete with a petting zoo) to the public.
June 1981 — The American Society of Mechanical Engineers (ASME) places a plaque beside the 100-inch telescope, designating it a Mechanical Engineering Landmark.
June 1985 — Carnegie Institution of Washington closes down the 100-inch telescope and withdraws financial support from Mount Wilson Observatory.
June 29, 1988 — "First Fringes" for Charles Townes' UCB Infrared Spatial Interferometer (ISI).
June 2, 1990 — Stephen Hawking visits Mount Wilson Observatory.
June 13, 1996 — Groundbreaking ceremony for Georgia State University’s CHARA Array.
June 21, 1997 — First propagation of an ultraviolet laser into the atmosphere by the University of Illinois' UNISYS laser guide-star adaptive optics system on the 100-inch telescope.
July 1, 1917 — Decked in red, white, and blue bunting, the 100-inch mirror arrives at Mount Wilson, after an arduous trip up the Toll Road on a gasoline-powered truck. This mirror, cast from wine-bottle glass at the Saint-Gobain Glass Works near Paris, had been undergoing grinding and polishing in the Observatory's shop in Pasadena since its delivery from France in 1908. The 100-inch telescope saw "First Light" on November 2, 1917, but was not put into regular use until a year later because of the demands of WW I.
July 19, 1917 — Mount Wilson astronomer George Ritchey discovers a supernova in galaxy NGC 6946.
July 6, 1938 — Mount Wilson astronomer Seth Nicholson discovers the 10th satellite of Jupiter.
July 30, 1938 — Nicholson discovers the 11th satellite of Jupiter.
July 6, 1989 — Maximum temperature at Mount Wilson 98 degrees F, minimum 78 degrees F.
July 2, 1991 — Maximum temperature at Mount Wilson 98 degrees F, minimum 76 degrees F.
July 13, 1996 — Groundbreaking ceremony for the CHARA Array. This six-telescope interferometer array, built at Mount Wilson by Georgia State University's Center for High Angular Resolution Astronomy, succeeded in combining light from the two most separated telescopes in the array (1,086 feet apart) in September, 2001. The array, designed to operate in both visible and near-infrared light, is currently doing scientific work in a number of areas of high-resolution astronomy, including the oblateness of fast-rotating stars, the size and shape of cepheid variable stars, the separation of binary stars, and the extent and diameter of dust clouds around young stellar objects.
August 1904 — In his first summer at Mount Wilson, Hale supervises construction of the "Monastery" living quarters (designed by renowned Pasadena architect Myron Hunt) while the materials for the Snow telescope are being transported up the mountain trail from Altadena and construction of this first of the Mount Wilson telescopes is begun.
August 31–September 9, 1910 — The International Solar Union meets at Mount Wilson. With 47 delegates from the United States plus 37 from foreign countries, this was the largest astronomy meeting ever held up to this time.
August 24, 1937 — Mount Wilson staff astronomer Olin Wilson discovers first Wolf-Rayet star.
August 21, 1993 — First remote operation of the 24-inch TIE (Telescopes in Education) telescope.
August 1990 — First CUREA (Consortium for Undergraduate Research and Education in Astronomy) session begins. This two-week, in-residence educational program, founded by Ohio State astronomer Joe Snider, has been held at Mount Wilson Observatory every summer since then.
September 19, 1904 — George Ellery Hale orders the mirror blank for the 100-inch telescope from the Saint Gobain Glass Works, Paris, which also cast the 60-inch mirror. Ordinary wine-bottle glass was used for both mirrors. Saint-Gobain is famous for having cast the mirrors for King Louis XIV's Palace of Versailles.
September 23, 1904 — En route to Washington, D.C., to lobby with the Carnegie Institution for Mount Wilson funding, Hale stops at the St. Louis World's Fair. Acting as Chairman of the Committee on Solar Research of the National Academy of Sciences, he gives the opening address at the Academy's conference at the fair.
September 22, 1917 — 100-inch mirror is installed in the telescope. The 100-inch saw "first light" on November 2, 1917, but was not used for research until after World War I ended in November 1918.
September 12, 1919 — Fires threaten mountain for two weeks.
September 29, 1951 — Seth Nicholson discovers 12th satellite of Jupiter with the 100-inch telescope.
September 20, 1986 — "First fringes" on U.S. Navy’s Mark III stellar interferometer at Mount Wilson. The Mark III served as a test bed for many of the techniques of modern interferometry.
September 6, 2000 — A third telescope is added to the UC Berkeley ISI interferometer. The ISI array, designed by Nobel Laureate Charles Townes, has done pioneering work in infrared stellar interferometry.
September 20, 2001 — "First fringes" over the longest (331 meter) CHARA interferometer baseline.
October 2, 1894 — As a birthday present for his son, George Ellery Hale's father, William Hale, orders a 60-inch mirror blank from the Saint Gobain Glass Works in France. Later ground and polished in the Carnegie Institution's Pasadena optical shop, this became the mirror for the Mount Wilson 60-inch telescope in 1908.
October 1904 — Hale spends most of this month in New York City and Washington, D.C., talking to Carnegie officials about funding for the proposed Mount Wilson Observatory. As he finds out two months later, his efforts there were a brilliant success.
October 28, 1915 — Billiard table arrives at Mount Wilson's Hooker Cottage.
October 5, 1923 — Edwin Hubble finds a Cepheid variable star in M31, the Andromeda Galaxy, which allows its distance to be measured. The value of about a million light years placed M31 well outside our own Milky Way Galaxy and revealed the true vastness of the Universe.
October 19, 1923 — R.G. Aitken discovers Mira companion predicted by Alfred Joy.
October 27, 1987 — Intention of Mount Wilson Institute to operate the Observatory is announced publicly at a press conference at Hale Solar Lab.
October 3, 1993 — Renovated Snow solar telescope is rededicated on its 90th birthday. This instrument was first dedicated on Oct. 3, 1903, at its original location on the grounds of Yerkes Observatory, Williams Bay, Wisconsin.
October 29, 1993 — Altadena fire reaches to within 1¼ miles of Mount Wilson Observatory.
October 4, 1999 — First closed-loop operation, with a natural star, of the University of Illinois' UnISIS adaptive optics system mounted on the 100-inch Hooker telescope.
October 4, 2000 — Georgia State University's CHARA array is dedicated.
October 19, 2003 — Carnegie Observatories presents "Artists Celebrate the Cosmos," an exhibition of paintings made at Mount Wilson Observatory, at an Open House celebrating the Observatory's Centennial.
November 20, 1889 — Mount Wilson astronomer Edwin P. Hubble is born.
November 12, 1891 — Mount Wilson astronomer Seth B. Nicholson is born.
November 1891 — 23-year-old George Ellery Hale becomes co-editor of The Sidereal Messenger, a popular astronomy magazine which he promptly re-names Astronomy and Astrophysics. He writes to a friend, "Stay away from editorial work—it's the most time-consuming thing in the world." This co-editing arrangement lasted less than three years; by 1894 Hale had decided to found his own magazine on astrophysics.
November 3, 1892 — The University of Southern California agrees to sell the lens blanks for the Alvan Clark 40-inch refractor to the University of Chicago for the then-new Yerkes Observatory.
November 2, 1894 — First meeting of the Editorial Board for a new magazine on astrophysics instigated by Hale. The group, which included such names as Albert Michelson, Henry Rowland, Charles Young, Charles Hastings, E.C. Pickering, and James Keeler, chose the title The Astrophysical Journal, an International Review of Spectroscopy and Astronomical Physics. The first issue appeared in 1895.
November 16, 1898 — Hale's father, William Ellery Hale, dies.
Early November, 1909 — Hale personally studies the planet Mars with the recently completed 60-inch telescope. Hale biographer Helen Wright describes this in her book Explorer of the Universe:
"In the fall of 1909 the planet Mars was making a close approach to the earth. Percival Lowell's imaginative writings on the 'canals' had roused intense popular excitement, and Hale was bombarded with questions from those who wanted to know if the canals were built by human beings. He doubted if there was anything in it, but he wanted to see for himself what Lowell might be calling 'canals.' One clear night he turned the 60-inch on the red planet. He saw some definite markings—'one of those so-called canals'—but they were totally unlike Lowell's drawings. These observations were made visually. Later he took photographs. He examined the famous marking known as Dawes' Forked Bay. With a low power, it looked like Lowell’s drawing 'except that the canals extending from the two extremities were vague and diffuse and by no means narrow and sharp.' With high power, he could see the two forks as rounded and irregular in outline, 'made up of interlacing and curved filaments.' They were so fine that they could not possibly be seen with small aperture or low powers. He was convinced that Lowell's 'canals' were largely a figment of his imagination. He reported his findings to the noted Italian expert on Mars, Giovanni Schiaparelli. Nevertheless, the majority of the public remained unconvinced. It preferred to believe in a Mars inhabited by fantastic beings."
The Dawes' Forked Bay is today called Sinus Meridiani (zero Martian longitude has been drawn right between the two forks). This is the very place where the Opportunity rover is now driving around exploring the geology. Hale was right. We now know for certain that the canals were an illusion and that Lowell's eyes had deceived him. See the Everest Panorama for a view as if you were standing on Mars (from the Spirit rover on the opposite side of the planet). What a difference 100 years makes!
November 1, 1915 — First billiard game is played on Mount Wilson.
November 2, 1917 — "First light" on 100-inch telescope, as the just-finished instrument—then the world's largest—is used for the first time. Hale made this cryptic note in his diary: "Friday, November 2, 1917—With Alfred Noyes to Mountain. First observations with 100—Jupiter, Moon, Saturn." When the small group first looked into the telescope, they were horrified to see multiple images—evidently caused by the sun shining on the mirror earlier that day and heating it enough to produce distortion. They waited for the mirror to cool, looked again several hours later, and then the images were perfect.
The "Alfred Noyes" he refers to was an English poet who was spending the year as a visiting lecturer at the Throop Institute in Pasadena. During the wait at the telescope, Hale spoke at length with Noyes, their conversation ranging from the war in Europe, then in progress, to poetry. According to Helen Wright, Hale said to Noyes, "You poets write of many things, but you never write of the development of science in the modern world. You write of wars. Why don't you write instead of the fight for knowledge?" Out of that chance remark came Noyes' book-length epic poem on the growth of astronomy over the centuries, Watchers of the Sky. In the book's prologue, Noyes gives this picture of that memorable night on Mount Wilson:
"Up there, I knew
The explorers of the sky, the pioneers
Of science now made ready to attack
That darkness once again, and win new worlds…"
November 10, 1942 — Mount Wilson astronomer Edison Pettit discovers Nova Puppis.
November 23, 1999 — "First fringes" on CHARA array.
December 19, 1852 — Albert A. Michelson is born.
December 31, 1864 — Mount Wilson Observatory optician/telescope designer George W. Ritchey is born.
December 20, 1876 — Mount Wilson astronomer Walter S. Adams is born.
December 21, 1898 — Mount Wilson astronomer Ira S. Bowen is born.
December 13, 1904 — Carnegie Institution of Washington's Board of Trustees meets to consider proposal by George Ellery Hale to establish a solar observatory on Mount Wilson. After considerable debate, a motion is passed to appropriate $310,000 for the observatory—subject to the approval by the CIW Executive Committee.
December 20, 1904 — CIW Executive Committee approves the Board's recommendation, appropriating $150,000 a year for two years. That same day, Hale, riding a mule on the Mount Wilson trail, receives a telegram at Martin's Camp with the momentous news. This date marks the founding of Mount Wilson Observatory.
December 7, 1908 — Mirror blank for 100-inch telescope arrives in Pasadena from Saint-Gobain Glass Works in France.
December 8, 1908 — "First light" on 60-inch telescope.
December 20, 1908 — First photographs are taken with the 60-inch telescope. Hale reported that the results were "admirable"—the star images small and perfect, the Orion Nebula beautifully defined.
December 13, 1920 — First stellar diameter (Betelgeuse) is measured by Francis Pease with 20-foot interferometer mounted on the 100-inch telescope.
December 17, 1987 — Maximum temperature at Mount Wilson is 23ºF, minimum 14ºF.
December 22, 1990 — Temperature at Mount Wilson falls to 10ºF.