Bailey, Solon Irving

(b. Lisbon, New Hampshire, 29 December 1854; d. Norwell, Massachusetts, 5 June 1931)

astronomy, meteorology.

Bailey pioneered in studies in the southern hemisphere for the Harvard Observatory, at a time when there were no large telescopes south of the equator. His two main contributions to astronomy were studies of variable stars in globular clusters and his longexposure photographs, which not only helped to elucidate the structure of our galaxy but also showed the value of photography in detecting extragalactic objects too faint to be observed visually.

Graduating from Boston University with an A.M. degree in 1884. Bailey began a career with the Harvard Observatory that was to last forty-four years. He earned a second A.M. degree from Harvard in 1888 and was then sent to South America by E. C. Pickering (director of the Observatory), to find a suitable location for Harvard’s proposed southern observing post.

Bailey traveled throughout Peru and Chile, trying out various sites. No information on weather patterns was available to make his task easier, so he established a chain of meteorological stations—from sea level up to 19,000 feet. He published the data that he accumulated over the following thirty-seven years in his “Peruvian Meteorology” (1889 to 1930). As a result of his survey, Harvard’s Boyden station, with the 24-inch Bruce doublet as its main telescope, was established near the city of Arequipa in Peru and remained in operation from 1890 until 1927.

Bailey took with him to Peru the visual photometer used for the original “Harvard Photometry,” a compilation of standard magnitudes for stars located north of declination —30° (1884, 1885), and with it completed Harvard’s coverage of the sky (1895). He then began photographing ω Centauri and other globular clusters, to get light curves for over a hundred of the stars now called cluster variables (1902, 1916); this work proved fundamental to estimates of astronomical distances subsequently made by Harlow Shapley and others.

Bailey’s photographs of regions in and away from the plane of the Milky Way were made with exposures ranging up to nineteen hours and twenty-seven minutes (1908, 1913, 1917). They were used for relative star counts and also revealed more than 3,000 new extragalactic objects.

Bailey served as acting director of the Harvard Observatory from 1919 to 1921, between the tenures of Pickering and Shapley. During his fifth and final stay in Arequipa, in 1923, the University of San Agustin awarded him an honorary Sc.D. degree. His other honors included election to the National Academy of Sciences in Washington. After retiring in 1925 he completed his History and Work of the Harvard Observatory, 1839-1927 (1931).

BIBLIOGRAPHY

I. Original Works. Except for the History and Work of the Harvard College Observatory, 1839-1927, which was published as harvard Observatory Monograph No. 4 (Cambridge, Massachusetts, 1931), all works cited in the text appeared in Annals of the Astronomical Observatory of harvard College. The original “Harvard Photometry” had appeared as “Observations with the Meridian Photometer during the years 1879-1882,” by E.C. Pickering, Arthur Searle, and Oliver C. Wendell, in Annals, 14 , part I (1884), I-324, and 14, part II (1885), 325-512; Bailey’s extension of it was “A Catalogue of 7922 Southern Stars Observed with the Meridian Photometer during the wars 1889-1891” (reduced under the direction of E. C. Pickering), ibid., 34 (1895), 1-259. The other papers by Bailey were “A Discussion of Variable stars in the Cluster ω Centauri,” ibid., 38 (1902), 1-252; “Globular Clusters,” ibid., 76(1916), 43-82; “A Catalogue of Bright Clusters and Nebulae,” ibid., 60 (1908), 199-229; “The Southern Milky Way,” ibid., 72 (1913), 71-78, with 9 half-tone plates; and “The Northern Milky way,” ibid., 80 (1917), 83-89, with 9 half-tone plates.

Bailey’s “Peruvian Meteorology,” covering the period 1888-1925, appeared in the Annals in six parts: 39 , part I (1889), 1-153; 39 , part II(1906), 157-292; 49 , part I (1907), 1-103; 49 , part II (1908), 107-232; 86 , part III (1923), 123-194; and 87 , part 2A(1930),179-217.

II. Secondary Literature. Annie Jump Cannon wrote two obituaries of Bailey: one in Monthly Notices of the Royal Astronomical Society, 92 (1932), 263-266; the other, with a portrait, appeared in Publications of the Astronomical Society of the Pacific, 43 (October, 1931), 317-323 and was reprinted, with the addition of a list of 95 publications by Bailey, in Biographical Memoirs of the National Academy of Sciences (Washington), 15 (1934), 193-203.

Sally H. Dieke