Douglass, Andrew Ellicott
Born Windsor, Vermont, USA, 5 July 1867
Died Tucson, Arizona, USA, 20 March 1962
Andrew Douglass’s primary training and lifelong ambition was in astronomy; he made substantial contributions to that discipline, particularly in demonstrating and articulating the impact of local atmospheric conditions on the effectiveness of astronomical observatories and in founding the Steward Observatory at the University of Arizona. However, Douglass is better remembered today as the founder of the science of dendrochronology, or tree-ring dating, as he spent a lifetime seeking to prove that the 11-year solar cycle affects the Earth’s climate and that tree-ring evidence would demonstrate that. His biographer, George Ernest Webb, argues that it was tree-ring dating that was Douglass’s only significant contribution to science.
Douglass was born in a privileged family descended from Vermont clergymen and educators. He was named after his paternal great-grandfather, Andrew Ellicott (1754–1820), a talented astronomer and surveyor. Ellicott assisted Pierre L’Enfant in platting what eventually became the capitol city of Washington. The fifth of six children, Andrew’s father was the Reverend Malcolm Douglass, who would later become a president (1871–1872) of Norwich University, Northfield, Vermont. Andrew’s mother, Sarah Elizabeth Douglass, was the daughter of Benjamin Hale, president of Hobart College, Geneva, New York. His grandfather, David Douglass, had been president of Kenyon College (Gambier, Ohio). Andrew was a brilliant student who achieved honors at Trinity College in physics, geology, and astronomy. Although he had no formal degrees beyond the baccalaureate level, he was the recipient in later years of an honorary doctorate bestowed upon him by his alma mater.
Douglass spent his first 5 postgraduate years as an assistant at the Harvard College Observatory in Cambridge, Massachusetts. His tenure at Harvard included a successful foreign assignment in Arequipa, Peru. Douglass accompanied William Pickering , who established a field station there for the university. After a year in Peru, during which Douglass acquired a taste for archeology and anthropology, he accompanied Pickering on a circuitous tour of European observatories before returning to Harvard. Back in Cambridge, Douglass reduced the observations that continued to flow in from Peru.
In 1892, Percival Lowell decided to expand upon his own interests as an amateur astronomer and take up the observation of Mars. By January 1894, that interest had expanded to involve assistance from Harvard. On Pickering’s recommendation, Lowell sent Douglass to the Arizona Territory in February to assess possible sites for an observing station for the viewing of Mars at the 1894/1895 opposition. In April 1894, on the basis of Douglass’s observations made at various locations around the Territory, Lowell selected Flagstaff as the site of the temporary observing station that eventually became the Lowell Observatory. Douglass was given the task of turning a hilltop that was only a mile west of the center of town into a temporary astronomical observatory, a task that he accomplished successfully by soliciting the cooperation of Flagstaff officials and residents. Observations of Mars began in late May and continued until the end of that opposition in April 1895.
Although Lowell’s needs dominated use of the telescope in favorable weather, Douglass participated in the observation campaign and remained at Flagstaff for the entire opposition event. At Lowell’s behest, Douglass made two trips to Mexico, searching for an even better site for a formal installation, while interspersing these times with returns to Harvard and data-reduction and writing efforts. As it happened however, Douglass remained in Flagstaff for a number of years managing what was becoming the permanent Lowell Observatory while Lowell himself was recovering from a nervous breakdown.
During this period, Douglass reduced observations, published the first two volumes of the Publications of the Lowell Observatory, and wrote numerous journal and periodical articles about the work of his mentor’s observatory, planetary astronomy, and other topics. Indeed, Edward Barnard thought so highly of Douglass’s observations and writing skills that he encouraged Douglass to send more of what Barnard “esteem[ed] … among the freshest and best that we get from any source.” Douglass continued to observe the satellites of Jupiter especially seeking to better understand their particular characteristics. It was during this time that his relationship with Lowell gradually unwound under the pressure of Douglass’s increasing sensitivity to reactions from the rest of the astronomical community to Lowell and his first book on Mars, controversy about the clouds observed on the terminator of Mars, Lowell’s insistence on the seeming presence of canals on the Red Planet, Lowell’s resistance to experimental observational work with model planets, etc. Of particular note was Douglass’s sighting of a bright flash along the Martian terminator that Lowell took to be a “message” sent from civilizations he believed present on the planet. Lowell published a book on the subject and was ridiculed by many in the community. George Hale already had refused to publish Lowell’s works in his fledgling Astrophysical Journal. But it was an unfortunate instance of Lowell’s receiving a copy of a letter critical of him written by Douglass to Lowell’s brother, William L. Putnam, seeking intercession concerning Lowell’s penchants with Mars, which finally led Lowell to fire Douglass. This was primarily because Lowell had become an obsessed devotee of Giovanni Schiaparelli and his canali, infamously mistranslated as canals, even though William Campbell had shown by spectroscopic analysis that the atmosphere of Mars was more akin to that of the Moon than to that of Earth. Little water vapor seemed present. Douglass could not abide Lowell’s insistence upon there being civilizations on Mars. Lowell’s pique led to his sudden termination of Douglass in July of 1901, thus leaving the younger astronomer trapped in the Wild West and unemployed after some 17 years in his chosen discipline, with 8 of those years spent in Flagstaff.
He was for a short time jobless, as there were no openings in astronomy on either coast of the United States, and so Douglass had to find a way to sustain himself in Flagstaff. He eventually won election as a local probate judge, and later taught at what is now Northern Arizona University. On 1 July 1905, he married the former Ida Whittington of Baltimore, Maryland and, in 1906, moved to the University of Arizona, Tucson, after 12 years in Flagstaff. Douglass remained at the university in Tucson for the rest of his extraordinarily long and productive life, although for many decades he continued to hope to return to his native Northeast, often applying for openings in various observatories or universities there.
It was during the years between the Lowell Observatory and the move to Tucson that Douglass became interested in tree rings. This led him to the de novo creation of the science of tree-ring dating, or dendrochronology, which became his primary concern as a technique to study the 11-year solar cycle, his all-consuming passion in astronomy. The dating of the great pueblos of the American Southwest, which had been engineered by the ancient Anasazi Indians and a problem that had vexed North American archaeology since the “cliff dwellings” and similar structures were first discovered, constituted Douglass’s greatest success story for dendrochronology (late 1920s). However, its role as a tool for astronomy was never realized. McGraw has stated, “the climatological records in the rings of trees would … be his entrepotto proving that the possible relationship of the 11-year sunspot cycle to weather patterns on Earth was indeed a reality.” He never succeeded in this; nor has anyone else done so beyond reasonable doubt, to this day.
Douglass held numerous positions at the University of Arizona, from professor to dean to director of Steward Observatory, including even its presidency for a short time. He sought to found an observatory almost from the day of his arrival in Tucson and, while it took two decades to actually open the facility, he was successful in obtaining funding (in 1916) from a Mrs. Lavinia Steward, whose deceased husband had been an amateur astronomer. Getting the primary instrument built, let alone the protective structure for it, was a prolonged and convoluted project, but when completed the Steward Observatory had a 36-in. Brashear/Warner & Swasey reflecting telescope. It was one of the larger telescopes available in US astronomical research institutions at the time of the observatory’s opening in April 1923.
Douglass left two physical, as well as intellectual, monuments to his long and busy career, the Steward Observatory and eventually (1935) the Laboratory of Tree-Ring Research, both on the campus of the University of Arizona and both of which remain major forces in their respective areas. In his efforts to study the 11-year solar cycle, however, Douglass also invented two optical instruments – the periodograph and its successor the cyclograph – to study the periodicity and cyclicity he believed he had found in tree rings.
- — (1898). “The First Satellite of Jupiter.” Astonomische Nachrichten146: 346–355.Google Scholar
- — (1899). “Mars.” Popular Astronomy7: 113–117.Google Scholar
- — (1918). “The Steward Observatory of the University of Arizona.” Publications of the Astronomical Society of the Pacific30: 326–330.Google Scholar
- — (1919). Climatic Cycles and Tree Growth: A Study of the Annual Rings of Trees in Relation to Climate and Solar Activity. Washington, DC: Carnegie Institution. (This is the first of three such volumes; the others coming out in 1928 and 1936. These works present, better than any other, Douglass’s discipline of dendrochronology and help to establish his place in American and world science.)Google Scholar
- — (1935). “Dating Pueblo Bonito and Other Ruins of the Southwest.” National Geographic Society Contributed Technical Papers. Pueblo Bonito Series 1.Google Scholar
- McGraw, Donald J. (2001). Andrew Ellicott Douglass and the Role of the Giant Sequoia in the Development of Dendrochronology. Lewiston, New York: Edwin Mellen Press.Google Scholar
- Nash, Stephen Edward (1999). Time, Trees, and Prehistory: Tree-Ring Dating and the Development of North American Archaeology, 1914 to 1950. Salt Lake City: University of Utah Press.Google Scholar
- Strauss, David (2001). Percival Lowell: The Culture and Science of a Boston Brahmin. Cambridge, Massachusetts: Harvard University Press.Google Scholar
- Webb, George Ernest (1983). Tree Rings and Telescopes: The Scientific Career of A. E. Douglass. Tucson: University of Arizona Press.Google Scholar