PICKERING, EDWARD CHARLES

(b Boston, Massachusetts, 19 July 1846; d Cambridge, Massachusetts, 3 February 1919),

astronomy

Pickering, the elder son of Edward Pickering and Charlotte Hammond, was a descendant of one of New England’s oldest and most distinguished families. John Pickering, his first American ancestor, had emigrated from Yorkshire and settled in Salem, Massachusetts, in 1636, bringing with him the family coat of arms (a lion rampant) and the motto Nil desperandum. Timothy Pickering. Edward’s great grandfather, served in the cabinets of Washington and John Adams.

Pickering attended the Boston Latin School for five years, where he “studied little and learnt less.” Forced to memorize long passages of such works as Xenophon’s Anabasis, he acquired a great distaste for the classics. He did, however, find time to read mathematical works on his own, for example Charles Davies’ Legetidre’s Elements of Geometry and Trigonometry. Finding these more to his liking, he proposed entering the Lawrence Scientific School at Harvard, only to be informed by his schoolmaster that the “only requisite would be to know enough to come in when it rained.”

Pickering entered the chemical department of the Lawrence Scienuik School in 1862. largely on the advice of Charles Willaim Eliot, then assistant professor of mathematics and chemistry. There he “found studies hard but delightful and enjoyed work exceedingly.” That spring, although offered a position as assistant instructor, he declined it on Eliot’s advice and entered the engineering department. He graduated summa cum laude i 1865 in his nineteenth birthday.

After two years as assistant instructor of mathematics at the Lawrence Scientific School, Pickering was appointed assistant professor of physics at the recently founded Massachusetts Institute of Technology. During his ten years there, he revolutionized the teaching of physics. With the encouragement of the Institute’s founder and president. William Barton Rogers, Pickering established the first physical laboratory in America specifically designed for student instruction. He devised a series of experiments on the construction and use of apparatus, the properties of gases, and the mechanics of solids, and wrote instructions to enable students to perform them. The students were further encouraged to design experiments and to publish their original research. Pickering later compiled the instructions he had written and published them as Elements of Physical Manipulation (2 vols. [Boston, 1873–1876]), thereby producing the first American laboratory manual of physics.

On 10 October 1876 Eliot, who had been elected president of Harvard in 1876, appointed Pickering director of the Harvard College Observatory. Pickering and his wife, Elizabeth Wadsworth Sparks (the daughter of Jared Sparks, a noted historian and former Harvard president), moved to Observatory Hill on 1 February 1877; and he began work that very day. Eliot’s selection of a physicist for the post rather than an observational astronomer evoked considerable criticism. Eliot, however, had sound reasons for his appointment: he had known Pickering both as an undergraduate at the Lawrence Scientific School and as a colleague on the MIT faculty, and was thoroughly familiar with his unusual scientific and administrative abilities. It is also possible that Eliot was aware that the direction of astronomical research was undergoing a crucial change.

Pickering realized at once that the greatest opportunities in astronomical research lay in the new field of astrophysics rather than in the astronomy of position and motion, which had occupied the chief place in the programs of other observatories. This is not to say that he ignored the“old” astronomy—several members of the observatory staff spent twenty years in preparing each of the two Harveard zones of the Astronomische Gesellschaft’s star catalog— but the astrophysicial work accomplished under his directorship was of incomparably greater volume and importance. He was a pioneer in three main fields of astronomical research: visual photometry, stellar spectrosocopy, and stellar photography.

Before Pickering began his photometric measurements, he made two important decisions: (I) he adopted the magnitude scale suggested by Norman Pogson in 1854, whereby a change of one magnitude represents a change of a factor of 2.512 in brightness, and (2) he chose a Ursae Minoris (Polaris), then thought to be of constant brightness, as the standard and arbitrarily assigned a magnitude of 2.1 to it. Working in close cooperation with George B. Clark, Pickering designed and had the firm of Alyan Clark and Sons construct several new models of photometers. This culminated in the development of a revolutionary new instrument, the meridian photometer, in which the image of a star crossing the meridian is brought alongside the image of Polaris by suitable arrangement of mirrors and prisms. Thus each star could be measured at its point of highest visibility.

This photometric work continued for nearly a quarter of a century. Pickering never tired of the routine work involved and made more than 1.5 million photometric readings. The brightness of every visible star was measured and re measured to obtain the greatest possible accuracy. The photometric studies culminated in 1908 with the publication of the Revised Harvard Photometry. Printed as volumes 50 and 54 of the Anals of Harvard College Observatory, it lists the magnitudes of more than 45,000 stars brighter than the seventh magnitude and remained the standard reference until photographic methods largely supplanted visual ones.

Pickering’s researches in stellar spectroscopy were made possible largely through the establishment of the Henry Draper Fund in 1886. Under the terms of this fund, Mrs. Draper supplied money to the Harvard observatory for Pickering and his assistants to photograph, measure, and classify the spectra of the stars and to publish the resulting catalog in the Anals as a memorial volume to Henry Draper. The program consisted of three main parts: a general survey of stellar spectra for all stars north of —25° and brighter than the sixth magnitude; a study of the spectra of the fainter stars: and a detailed investigation of the spectra of the brighter stars.

The spectra were produced by placing a large prism in front of the telescope’s objective. While this did not give the definition attainable by use of a spectroscopic slit, it allowed a large number of spectra to be photographed on a single plate and gave sufficient definition. The principal investigators on the project were Williamina P. Fleming, Annie Jump Cannon, Antonia C. Maury (Henry Draper’s niece), and a large corps of women computers. This led some contemporary wags to refer lo the Harvard team as “Pickering and his harem.”

These investigations culminated with the publication of The Henry Draper Catalogue, printed between 1918 and 1924 as volumes 91–99 of the Anala. In this work nearly a quarter of a million stellar spectra were measured by Annie Jump Canon and placed into one of twelve main spectral classes (P, O, B, A, F, G, K, M, R, N, Continuous, and Peculiar), This system was unanimously adopted by the International Union for Cooperation in Solar Research but was later modified slightly by the Committee of the International Astronomical Union on Spectral Classification.

The third principal field of Pickering’s research was stellar photography. As early as 1883 he decided to chart all of the visible stars by means of photography. At the International Astrophotographic Congress organized in 1887 at Paris, however, it was decided that several observatories would participate in preparing a photographic atlas of the sky. Although the Congress intended to publish a map of the heavens in about five years, progress was so slow that Pickering maintained his desire to issue his own photographic map of the sky (the Carte da del is still incomplete). The acquisition of a substantial fund enabled him to carry out his plan. In 1889 Catherine Wolf Bruce, responding to a circular Pickering had issued, donated money for a large photographic telescope. The Bruce telescope, employing a photographic doublet with a twenty-four-inch aperture ground by the Clarks, was completed in 1893; and after a year and a half of testing, it was shipped to Harvard’s Boydcn Station at Arequipa, Peru, where it was used routinely in Photographing the heavens.

In 1903 Pickering issued a Photographic Map of the Entire Sky, the first such map ever published, but it was not made with the Bruce telescope. Instead, two 2.5-inch doublets were used in Cambridge and Arequipa to map stars down to the twelfth magnitude on fifty-five plates. In addition, Pickering’s habit of routinely photographing as large a portion of the visible sky as possible on every clear night resulted in the Harvard Photographic Library, which provides a photographic history, on some 300,000 glass plates, of all stars down to the eleventh magnitude. This record, duplicated nowhere else, is heavily relied on today by astronomers everywhere.

Other investigations that Pickering undertook were in photographic photometry. This was one of the chief interests of his later years, and an increasing part of the work of the observatory was devoted to establishing a standard system of stellar photographic magnitudes. The study of variable stars was also a marked feature of the observatory’s work during his administration, and Pickering was instrumental in the founding of the American Association of Variable Star Onservers. In 1889 he discovered that the brighter component of ζ Ursae Majoris (Mizar) was a spectroscopic binary—that is, a double star that is not resolvable in the telescope but which can be detected by the periodic doubling of its spectral lines. In 1886 he observed three systems of lines in ζ Puppis, the third of which formed a series closely resembling the Balmer lines of hydrogen. Pickering thought they represented hydrogen under some unknown conditions of temperature or pressure; Niels Bohr later showed that the “Pickering series” was actually due to ionized helium.

Pickering thoroughly believed in the advantages of broad associations in astronomy. One of his most cherished hopes was to organize a centralized institution to distribute funds to astronomers of all nations. He published several pamphlets on this subject, but his plan met with little success. For a short period Pickering was enabled to administer $500 gifts to American and European astronomers through another donation from Catherine Wolf Bruce. The establishment of the Carnegie Institution in 1902 raised his hopes, but he became bitterly disappointed when its executive committee made it clear that it preferred to support established observatories and other enterprises of its own creation rather than individual scientists. In 1906 he approached the Rockefeller Foundation for funds to implement another of his plans, the establishment of an international southern telescope at some favorable site, preferably in South Africa. Again he met with no success.

During his lifetime Pickering received numerous awards and honors. Six American and two European universities bestowed honorary doctorates upon him, and he was made a knight of the Prussian Ordre Pour Je Merite. Besides being a member of the American scientific societies, he was cither a member or a foreign associate of the royal or national societies of England,France, Germany, Italy, Ireland, Sweden, Mexico, and Russia. He was awarded the Henry Draper Gold Medal of the National Academy of Sciences, the Rumford Gold Medal of the American Academy of Arts and Sciences, the Bruce Gold Medal of the Astronomical Society of the Pacific, and the gold medal of the Royal Astronomical Society on two occasions.

In all of his astronomical investigations, Pickering was not a speculator or theorizer but was content to be, in his words, “a collector of astronomical facts.” Whereas theoretical reasoning not based on well-established data had little attraction for him, the posthumous value of the work of William Herschel and Friedrich Argelander appealed strongly to him. Recognizing that the best service he could render to astronomy was the accumulation of facts, he instituted great research projects, often of a considerably routine nature, so that a sufficient basis in fact could be established for the solution of stellar problems by future astronomers.

When Pickering died in 1919. the Harvard College Observatory had been in operation for eighty years and he had been its director for forty-two of those years. Such a vast network of correspondence was established with observatories and astronomers throughout the world that the Harvard observatory under Pickering became the major distributing house of astronomical news. There was virtually no astronomer active during this period who did not benefit in one way or another from Pickering’s interest and assistance. Indeed, many of his fellow astronomers thought of him as “the dean of American science.”

BIBLIOGRAPHY

I. original works. An extensive bibliography of Pickerings works numbering 266 items, prepared by Jenka Mohr, is appended to Solon I. Bailey, “Biographical Memoir of Edward Charles Pickering,” in Biographical Memoirs. National Academy of Sciences, 15 (1934), 169–178. This bibliography does not include Pickering’s contributions to the Bulletin. Astronomical Observatory, Harvard College or to Circular. Astronomical Observatory of Harvard College (many of which are unsigned), nor does it include the anual Report. Astronomical Observatory of Harvard College.

Pickering’s papers are in the Harvard University Archives. The collection, which totals sixty-eight linear feet, includes personal and official correspondence, an autobiography, an autobiographical and personal notebook, and other notebooks and scrapbooks.

II. Secondary Literature. There is as yet no full length biography of Pickering. Bailey’s “Memoir” cited above is taken, with only slight alterations, from his History and Work of the Harvard Obsercatory (New York, 1931). A recent and extremely valuable account of Pickering’s observatory directorship can be found in Bessie Zaban Jones and Lyle Gitford Boyd, The Harvard College Observatory. The First Four Directorships, 1839– 1919 (Cambridge, Mass., 1971), more than half of which is devoted to the Pickering years.

Howard Plotkin

Edward Charles Pickering

The American astronomer Edward Charles Pickering (1846-1919) was a pioneer in the fields of stellar spectroscopy and photometry.

Edward Pickering was born on July 19, 1846, in Boston, Mass., of a distinguished New England family. After studying at Boston Latin School, he attended Lawrence Scientific School, graduating summa cum laude in 1865. He taught mathematics at that institution for a year and then moved to Massachusetts Institute of Technology, becoming Thayer professor of physics in 1868. He married Elizabeth Wardsworth Sparks in 1874.

In 1876 Pickering accepted the directorship of the Harvard Observatory, an appointment that both surprised and angered many, for he had no experience as an observational astronomer. The choice of a physicist, however, placed Harvard in the leadership of the trend, growing since the midcentury, toward a "new astronomy" which used the methods of the physicist to seek a knowledge of stellar structure and its evolution. The day of the observer, who noted the positions of heavenly bodies, was virtually over, and Pickering's appointment to such an important post may well have symbolized the victory of the new astronomy over the old.

The most important achievement of Pickering's directorate was in stellar photometry, a field barely explored with large instruments at the time. When he began the work, even the magnitudes of the stars were not fixed on any generally accepted scale. Pickering established a widely accepted scale and employed instruments, at least one—the meridian photometer—of his own invention, to achieve unprecedented accuracy in determining the magnitudes of 80, 000 stars.

Pickering's second work, begun in 1885, was the compilation of a "photographic library, " as he called it, giving a complete photographic chart of the stellar universe down to the eleventh magnitude on some 300, 000 glass plates. From such plates the past record of the stars may be studied; Pickering, for example, was able to plot the path of Eros in the sky from photographs taken 4 years before this asteroid was discovered.

Pickering was also a leader in stellar spectroscopy, laying the foundation for the method of spectral classification now universally accepted and obtaining the material for the Draper Catalogue, containing 200, 000 stars. He twice received the Gold Medal of the Royal Astronomical Society, was a member of the National Academy of Sciences, and was a founder in 1898 of the American Astronomical Society, of which he was later president. By the time of his death, on Feb. 3, 1919, he was generally recognized as one of the two or three outstanding astronomical researchers in America.

Further Reading

The only source of biographical data on Pickering is Solon I. Bailey, The History and Work of Harvard Observatory, 1839-1927 (1931). Bailey's memoir of Pickering, with a bibliography of Pickering's writings, is in National Academy of Sciences, Biographical Memoirs, vol. 15 (1934). □

Pickering, Edward Charles (1846-1919)

Distinguished astronomer and a founding member of the American Society for Psychical Research. He was born on July 19, 1846, in Boston, Massachusetts. He studied at the Lawrence Scientific School of Harvard University (B.S., 1865). After graduation he taught mathematics and physics at Lawrence (1865-67) and then became a professor of physics at the Massachusetts Institute of Technology (1868-77). In 1877 he was appointed director of the Harvard Observatory, a position he held for 42 years. Pickering devised methods of measuring the magnitudes of stars and supervised the cataloguing of some 80,000 stars. He also established the Harvard Observatory auxiliary station at Arequipa, Peru, in 1891.

In the field of parapsychology, Pickering was vice president of the American Society for Psychical Research from 1885 to 1888 and served on the society's Committee on Thought Transference. He participated in the statistical analysis of experiments in telepathy using cards, dice, and numbers, a precursor to the methods later championed by parapsychology. He died on February 3, 1919, in Cambridge, Massachusetts.

Sources:

Berger, Arthur S., and Joyce Berger. The Encyclopedia of Parapsychology and Psychical Research. New York: Paragon House, 1991.

Pickering, Edward Charles. "Possibility of Errors in Scientific Researches, Due to Thought-Transference." Proceedings of the American Society for Psychical Research 1 (1885).

Pickering, Edward Charles, and J. M. Peirce. "Discussion of Returns in Response to Circular No. 4." Proceedings of the American Society for Psychical Research 1 (July 1885).

Pleasants, Helene, ed. Biographical Dictionary of Parapsychology. New York: Helix Press, 1964.