THE lifelong friendship of Robert Patterson Lamont ('91e, A.M. hon. '12) and William Joseph Hussey ('89e, Sc.D. Brown '12) and the latter's special interest in double stars, are well known not only at Michigan but throughout the astronomical world. Hussey taught in the Department of Astronomy in 1891-92, and returned in 1905 for a long term of service as Professor of Astronomy and Director of the Observatory. He has related that in November, 1902, Lamont visited the Lick Observatory at Mount Hamilton, California, and that they had their first conversation concerning the desirability of sending a large telescope to the Southern Hemisphere for the measurement of double stars and for the extension of the doublestar survey to the south celestial pole. At that time Hussey and Aitken were conducting a joint program to cover the sky available at Lick (to -22° declination). By 1905 Hussey had discovered 1,338 pairs, but left his part of the work unfinished in order to return to the University of Michigan. This joint work won for both astronomers the Lalande prize of the French Academy, conferred in 1906.
Administrative duties and the construction of the 37 ½-inch reflecting telescope for astrophysical work demanded the major part of Hussey's time and attention until 1911. His dream of a southern station, however, was constantly kept in mind. On April 3, 1908, he and James H. Marks ('08e) went to Chicago to test the polar and declination axes for the large reflector at the Elmer Engineering Works. In the evening Hussey and Lamont attended a world-championship wrestling match. The next day at lunch Hussey spoke of his desire to proceed Page 477with the preparation of plans for a twenty-four-inch refracting telescope for the Southern Hemisphere, and Lamont promised $1,000 with which to begin. The check arrived on June 14. At this time also began the delays and disappointments that extended over nearly a quarter of a century, during which Hussey's vision never faded and Lamont's loyalty never faltered.
Other problems intervened. One of the first involved the protection of the Observatory site at Ann Arbor, which necessitated the purchase of adjacent property on the east. On October 2, 1908, Hussey wrote to Lamont explaining the situation, and said he needed $5,000 in cash to meet the emergency. So urgent did he think the need that he took the letter to the midnight train. Before the reply came, a bank loan of $6,000 was arranged, paid in due time by Lamont. In December he also agreed to buy a large lathe and a shaper for the Observatory Shop and to start the construction of the twenty-four-inch refractor.
Professor Hussey spent a day at the Naval Observatory with Mr. Marks in April, 1909, inspecting the twenty-six-inch refractor and the blueprints of it, and in that one day collected practically all the data that were needed for the design of the twenty-four-inch refractor. On February 20, 1910, during a visit to Ann Arbor, Lamont authorized placing the order for the glass for the refractor, and on March 7, under Hussey's direction, plans and drawings for the mounting were begun by Samuel Pierpont Langley ('08e), nephew of the celebrated astronomer of the same name.
A few days later occurred an interruption which Hussey evidently thought might be turned to good account. A cablegram was received March 12, 1910, from President Gonzalez of the National University of La Plata, offering him the directorship of the La Plata Observatory. Acting President Hutchins was consulted regarding the offer, and, according to Hussey's diary, advised him "not to take it," or, at any rate, "to be in no hurry about accepting it." Soon afterward, in Chicago, Lamont suggested that Hussey go and look it over, and offered to pay the expenses of his trip to South America.
Upon Hussey's return from Chicago, the gifts from Mr. Lamont were announced to the Regents — the twenty-six acres of land just east of the Observatory, the large lathe and shaper for the shop, and the glass for the twenty-four-inch objective. Hussey explained to them the La Plata offer, and arrangements were made for a leave of absence to permit him to go to investigate it and to report on the possibility of arranging plans by which the two observatories might co-operate.
On January 24, 1911, the 37 ½-inch reflector was ready for trial, but the night was not clear. On January 27 telegrams were exchanged with the La Plata representative in New York. The first spectrogram with the reflector, one of Capella, was made on January 31, 1911, and on February 5 at the Hotel Astor in New York a conference was held at which President Hutchins, Director Hussey, Lamont, and Ernest Nelson of the La Plata Observatory discussed plans of co-operation between the two observatories. It was proposed that Hussey hold the directorship of both and divide his time between the two. On February 23 the Regents approved his La Plata appointment, and on June 20 he boarded the "Voltaire" for South America.
Then followed several years during which he divided his time between the two institutions. During the year 1913-14 conversations were in progress with President Gonzalez to provide a larger telescope, "the largest in the world," at La Plata for spectroscopic work. "That Page 478here [at Ann Arbor]," wrote Hussey, "and the Lamont refractor at Cordoba on the hill would make a fine combination." That combination, however, was not to be. The National University of La Plata met with financial reverses. In 1915 even the publications of its observatory were held up: the treasury was empty. On September 13 Hussey was summoned back to Ann Arbor by a cablegram from President Hutchins informing him of the serious illness of Mrs. Hussey, who died before he reached home. His directorship at La Plata ended in 1916.
In the meantime, work on the Lamont refractor was not forgotten. In 1911 a contract for a twenty-four-inch objective was given to Alvin Clarke and Sons. At about the same time glass was ordered from Parra-Mantois and Company of Paris, but it was not obtained. Two years later a duplicate order was placed with the German firm Schott and Genoessen. But up to the time of Hussey's last return from South America the glass had not been received. Mr. Lundin, the expert optician selected to make the lens, had died in 1915. The World War then intervened. During this period there was improvement in the production of optical glass in the United States, and at the end of the war the glass was ordered anew from an American firm. Three more years passed without success. In August, 1922, in response to an inquiry, Hussey learned that at Jena was a pair of unsold disks twenty-eight inches in diameter suitable for a twenty-seven-inch objective. The American firm kindly consented to cancel the order. Lamont authorized the purchase of the Jena disks, which were received by McDowell and Company at Pittsburgh in April, 1923. Because of the tragic death of J. B. McDowell, chief optician, there was another delay, but the work was completed by Hageman and the objective reached Ann Arbor on January 27, 1925.
Early work on the mounting had been done in the Observatory Shop by Henry J. Colliau and was halted in 1913 awaiting final information regarding the diameter and focal length of the objective. The larger lens necessitated a new tube, which was constructed at the Observatory Shop, and adapted to the mounting, which needed only minor changes. During the summer of 1925 the twenty-seven-inch Lamont telescope was fully assembled and temporarily mounted just south of the dome of the 37 ½-inch telescope for final testing. The preliminary optical tests had been carried out at Pittsburgh, and the final test at Ann Arbor on star images, including selected double stars, proved entirely satisfactory. Tests made by Heber D. Curtis on the lens in the optician's works at Pittsburgh showed that it might well be termed "perfect" as to figure, and this has been borne out by the subsequent performance of the telescope in South Africa. A large proportion of Rossiter's pairs are of separation only 0."25 to 0."20, and experts have pronounced the discovery and measurement of many of these pairs as "an extraordinarily severe test for any observer with any telescope even under the best observing conditions."
The southern site for the Lamont refractor had been carefully selected after thorough investigation by Hussey, whose long experience had made him an expert along this line. In 1903 he had studied "seeing" conditions in southern California, Arizona, and Australia for the Carnegie Institution, and it was largely because of his recommendation that Mount Wilson, California, was approved as the site for that institution's 60-inch reflector and likewise, later, of its 100-inch reflector. During his South American experience, conditions at La Plata were adequately known by his discovery of 312 double stars, and he had given fairly favorable consideration to a site near Page 479Cordoba, Argentina. South Africa remained as a possible location, and in October, 1923, he left Ann Arbor, taking a ten-inch telescope with lens by McDowell, the mounting of the old six-inch telescope of the Students' Observatory at Ann Arbor, and a new tube. With this instrument he tested sites near Bloemfontein and Johannesburg and studied information received from reliable sources regarding other sites. He stated:
Dr. Innes, Director of the Union Observatory, recommended Johannesburg, or some place in its vicinity. The late Sir David Gill, for many years Director of the Royal Observatory at Cape Town, Colonel Morris, long associated with the South African Geodetic Survey, Dr. Halm, Acting Astronomer at Cape Town, and Senator A. W. Roberts of Lovedale, all recommended Bloemfontein, the capital of the Orange Free State.
(Hussey, MS, "Lamont-Hussey Observatory.")
Tests with the ten-inch telescope during December and January, 1923-24, confirmed these recommendations, and Naval Hill was finally selected. The site is within the city limits of Bloemfontein about two miles north and three hundred feet above the business section.*
In August, 1926, the Lamont refractor was shipped for Bloemfontein, and on October 9 Hussey, accompanied by Mrs. Hussey and Richard A. Rossiter with his family, sailed from New York. In London on October 28, 1926, while Professor Hussey was at dinner with friends, occurred his unexpected death, the most severe blow received by the southern project of the University of Michigan and a tragic ending of a lifelong dream just to be realized. S. W. Burnham, another famous American double-star observer, paid a fitting tribute when he said that Hussey's record in all fields of double-star work was brilliant and that it would not be forgotten as time went on.
Ralph Hamilton Curtiss, who came to the Observatory in 1907 and was in charge during Hussey's many absences, succeeded him, first as Acting Director, and then, in March, 1927, as Director of the Observatory. Also, immediately upon the death of Hussey, he was placed in charge of the Lamont expedition to South Africa. It was decided that the work should proceed under Rossiter, who continued from London and arrived at Bloemfontein November 28, 1926. A fifty-six-foot dome by Fecker of Pittsburgh and some accessories were shipped the following October.
Plans for the Lamont-Hussey Observatory Building were made by W. S. Lunn, engineer, of Bloemfontein, and the construction was let to a local firm there, W. H. Birtand Sons. Another Bloemfontein company, Gillespie and Son, erected the dome. Many favors were extended by the municipality, including a practically free site, road construction, water and power at cost, and a residence for Rossiter at one dollar rent per year.
The Lamont-Hussey Observatory building consists of the circular telescope room, fifty-six feet in diameter, and a north and a south wing. The central part is covered by the large dome of the twenty-seven-inch refractor. The south wing contains the library, three offices, a restroom, a storeroom, and a darkroom. The north wing provides quarters for the caretaker and for garage and storage purposes. The steel dome weighed fifty-eight tons when it was crated for shipment. It is rotated by a five-horsepower motor with a control at the switchboard and another within reach of the observer at the telescope. An observing chair twenty-seven feet high and of light steel construction, also built by Fecker, was provided to take the place of the elevating floor originally planned. Page 480The twenty-seven-inch objective of the Lamont refractor has a focal length of 40 feet and 7 ½ inches from the rear surface of the crown-glass component. The combination of crown and flint disks is corrected for visual light. The bronze cell designed by Colliau permits relative rotation of the disks for possible improvement of definition, which has not yet been deemed necessary. A few changes from the Warner and Swasey design for the mounting were made, including a differential slow motion in the drive, and a small increase in the thickness of the steel sheets of the tube to decrease the amount of flexure. The micrometer was patterned after the Warner and Swasey micrometer of the University's twelve-inch refractor at Ann Arbor, with improvements suggested by Hussey and made in the Observatory Shop. The adopted value of one turn of the screw is 10."540. Ten eyepieces giving magnifying powers from 240 to 1,760 are provided.
Morris K. Jessup and Henry F. Donner sailed from New York October 1, 1927, to assist Rossiter with the doublestar program. The Lamont-Hussey Observatory was dedicated on April 28, 1928, with guests present officially representing the Orange Free State, the city of Bloemfontein, and the Boyden Station of Harvard University. The staff formally began its work, carrying out in detail the plans originally formulated by Hussey. The following account of the program, its progress, present status, and future plans, was submitted by Rossiter, June 30, 1937, who remains as Michigan's only representative to carry to completion the comprehensive plans of Hussey's dream and Lamont's benefaction.
Former double-star programs customarily carried the systematic examination of stars through 9.0 or 9.1 catalogue magnitude. The searches at the Lamont-Hussey Observatory have been extended to include 9.5 catalogue magnitude. The majority of the charts from which the searches have been made were plotted to that magnitude at Ann Arbor under the direction of the late William J. Hussey. The part of the southern sky not covered by these charts is represented by charts used by Hussey at the Lick Observatory of the University of California or at the Argentine National Observatory at La Plata. Additional stars have been plotted at Bloemfontein on these old charts, and in many cases wholly new charts have been prepared. The search files of the Lamont-Hussey Observatory now contain 1,875 charts of the southern sky from -10° declination to the south pole in bands of declination four degrees wide. Each chart from -10° through -65° is 12m of right ascension wide by 4° of declination long. South of -65° the charts are of 24m or 36m of right ascension wide. The chart method has always been used at the Lamont-Hussey Observatory in searches, researches, and in remeasures. An observer using the chart method needs no assistant in the dome while he is working. The original searches and researches, and remeasures in the same or adjacent bands, are carried out very expeditiously and conveniently by a single observer by this method. The Lamont twenty-seven-inch refractor has no installed fine circles and thus far has not seriously needed them. Only a widely scattered group of double stars to be remeasured would make fine circles more convenient than the chart method.
Since all known southern double stars are indicated on these 1,875 charts, the total file represents a location catalogue of southern pairs. Of the more than 15,000 double stars thus entered on these charts 5,650 were found at the Lamont-Hussey Observatory during the period May, 1928 — May, 1937. In addition to Page 481this chart catalogue there are two card catalogues of Lamont-Hussey Observatory double stars, one in order of right ascension for all the 5,650 pairs and the other in order of right ascension in each four-degree band. All measures are entered on both sets of cards. Since both searching and measuring is carried out by four-degree bands, the second card catalogue is most convenient for first record and for entry into the first card catalogue. The first card catalogue is most convenient for publication and for general entry or comparison with published lists or measures.
Three observers have been responsible for finding the 5,650 Lamont-Hussey Observatory pairs. Morris K. Jessup, working during the period May, 1928 — July, 1930, is credited with 854 new double stars; Henry F. Donner, May, 1928 — May, 1933, with 1,057; and Richard A. Rossiter, May, 1928 — May, 1937, with 3,739. Each observer has been held responsible for securing sufficient measures of his own double stars to form, and furnish for double-star observers, a first epoch with which later measures might be compared. Only when some orbital motion is shown by a later epoch of measures does a double star become of especial interest to double-star observers. By January, 1930, 2,550 Lamont-Hussey Observatory double stars had been thus measured for a first epoch. To May, 1937, and particularly during 1935 and 1936, an additional 2,600 pairs have had first epochal measures. The remaining 500 double stars have had measures on only one night or need more measures to give a good first epoch.
Approximately 80 per cent of the southern sky has been searched at the Lamont-Hussey Observatory during the period May, 1928 — May, 1937. By means of part-time searches during the following three years the remaining 20 per cent should be finished. Plans for the five years ending in June, 1942, call for completion of the first epochal measures of all Lamont-Hussey Observatory pairs and as many second epochal measures as possible, an estimated 80 per cent of the total final list.
Of the 5,650 new double stars, 44 per cent are not fainter than 9.1 catalogue magnitude. The discoveries of the past two years still maintain approximately that percentage of standard search doubles. The number of faint close companions is greater than that in most lists of standard new double stars, and represents pairs only observable under reasonably good conditions of transparency and steadiness.
The magnitude-separation formula, adopted as a basis for determining which apparent double stars are to be retained in the files as Lamont-Hussey Observatory pairs, is as follows: log ρ" = 2.5 - 0.2m, where ρ" is the separation in seconds of arc and m is the combined visual magnitude of the two components of the double star. This formula allows a separation of 8."0 for an 8.0 visual magnitude pair; 5."0 for a 9.0; and 3."2 for a 10.0. Of the 5,650 Lamont-Hussey Observatory pairs, 94 per cent fall within the limits of separation set by this formula, and the remaining 6 per cent are borderline cases which have been retained if their separations are not greater than one-third wider than called for; 22 per cent of the 5,650 pairs are not wider than 0."5, 15 per cent are wider than 3."0, and the remaining 63 per cent thus have separations in the range from 0."5 to 3."0.
In the majority of cases the combined visual magnitudes of the Lamont-Hussey Observatory double stars have been determined by Rossiter with an iris diaphragm attached to the four-inch finder of the Lamont twenty-seven-inch refractor. The apertures used for the various magnitudes have been standardized by Page 482means of the Harvard photometric stars found in the Henry Draper Catalogue. For stars with components separated more than 3."5 the magnitude of the primary component seems to be given by the iris diaphragm; for components closer than 2."0 or 1."8 the magnitude is that of the combined light of the two components. For separations ranging from 2."0 to 3."5 an adjusted value between the combined light and the light of the primary seems best to represent the magnitude of the components as seen in the twenty-seven-inch refractor. Difference of magnitude between the two components must of course be estimated only in the large telescope.
No complete measures of any Lamont-Hussey Observatory pairs have yet been published by the University of Michigan or by the Lamont-Hussey Observatory. Single-line announcements for each double star, including an approximate measure, have been published in the Memoirs of the Royal Astronomical Society for 5,250 pairs, 2,232 in 1933 and 3,018 in 1936, in sections of Volume 65. Four hundred more are soon to be announced in similar manner. At the completion of the search and measuring program the University of Michigan will publish the whole list of Lamont-Hussey Observatory double stars, together with their first and second epochal measures, in a "Hussey Memorial Volume" in commemoration of one of the great double-star astronomers of the world, the late William Joseph Hussey, whose name is coupled with that of the Honorable Robert Patterson Lamont, the original donor of the Observatory and its great telescope.
The financial support of the Lamont-Hussey Observatory for the five years ending in June, 1933, came chiefly from the donor. Every assistance to the expedition was given by the government of the Union of South Africa and that of the Orange Free State, as well as by the municipality of Bloemfontein. It has been estimated that such assistance, in the form of a residence for Rossiter and low, fixed charges for electricity and other services, amounted to fully 10 per cent of the yearly expenses, and these have been cheerfully given from the beginning of the expedition until April, 1937, when an even more liberal measure of support was provided. From 1933 until April, 1937, the University of Michigan assumed the financial responsibility.
For the five-year period April, 1937 — March, 1942, the municipality of Bloemfontein furnished the total financial support for carrying on the Lamont-Hussey Observatory from a fund 80 per cent of which was furnished by the government of the Union of South Africa and 20 per cent by the municipality. By agreement the University of Michigan retained full ownership of the Observatory, of its equipment, of its observing program, and of the results secured, and has the financial responsibility of publishing the "Hussey Memorial Volume" at the completion of the observing program. Suitable acknowledgment is to be made in the final published volume for the financial support given by the municipality of Bloemfontein and the government of the Union of South Africa. The agreement thus allowed the Lamont-Hussey Observatory to carry on its program according to the plan pursued during the period May, 1928 — March, 1937, an agreement remarkable in its liberality of view and freedom from restrictions.