Reginald Daly was born in Napanee, Ontario, on March 18, 1871. He graduated from Victoria College in 1891, after which he remained at the University of Toronto for an additional year in order to teach mathematics and to acquire his S.B. degree. During this time he came under the influence of geologist A. P. Coleman and decided to pursue graduate studies in Earth science. He entered Harvard University in 1892, receiving his M.A. in 1893 and his Ph.D. 3 years later. Postgraduate study took him to Heidelberg, where he learned thin-section analysis, as well as to Paris, where he studied with Alfred Lacroix. In 1898, Daly returned to Harvard to serve as an instructor in geology, a post he retained until 1901, when he began a 6-year stint as field geologist with the Canadian International Boundary Commission. Returning to academia in 1907, Daly taught physical geology at the Massachusetts Institute of Technology for 5 years; he then accepted the position of Sturgis-Hooper Professor of Geology at Harvard. He retained this appointment until his retirement in 1942.
Beginning with his work at Mount Ascutney, Vermont (begun in 1893), Daly understood the importance of field studies in defining key questions about geologic processes. Thus his exhaustive examination of some 400 miles of terrain along the 49th parallel led to a theory of the origin of igneous rocks. Similarly, his expedition to the Samoan Islands, funded by the Carnegie Institution of Washington, resulted in theories of the relationship of sea level, mediated by glacial effects, on the formation of coral atolls. As a member of the Shaler Memorial Expedition to the southern hemisphere (1921–1922), Daly mapped St. Helena and the Ascension Islands, visited South Africa, and contributed to understanding the stratigraphy of the region.
Daly’s field studies also stimulated his theoretical speculations about rock mechanics and led to new questions about the Earth and its dynamic processes. He used these insights to great effect in the classroom, thus inspiring the next generation of Earth scientists, notably, petrologist Norman Bowen. Daly also developed many fruitful collaborations with scientists in other research areas. For instance, in an effort to understand the physical properties of rocks and rock melts, he worked with physicist Percy Bridgman at Harvard and with high-pressure researchers at the Geophysical Laboratory in Washington. He also wrote and lectured widely, sharing his views and enthusiasm with students and the general public alike. His text book Igneous Rocks and Their Origin appeared in 1914 and remained a staple for college instruction for many years.
For this diverse body of work, Daly received many honors, including honorary degrees from the University of Heidelberg, the University of Chicago, and Harvard University, as well as membership in the American Academy of Arts and Sciences (1909), the American Philosophical Society (1913), and the National Academy of Sciences (1925). He received the Penrose Medal from the Geological Society of America in 1935 and, despite his protestations of unworthiness, the William Bowie Medal from the American Geophysical Union in 1946. In his acceptance speech for the latter, Daly claimed to be a “tireless advocate of cooperation in Earth science,” and it is, perhaps, this breadth of vision and commitment to synthesis that defines his reputation today. He died in Cambridge, Massachusetts, on September 19, 1957.
—Robert M. Hazen
Carnegie Institution of Washington