The 1769 Transit of Venus

July 1, 1983

The Journal of San Diego History
SAN DIEGO HISTORICAL SOCIETY QUARTERLY
Summer 1983, Volume 29, Number 3
Thomas L. Scharf, Editor

Book Review

Raymond Starr, Book Review Editor

The 1769 Transit of Venus: The Baja California Observations of Jean-Baptiste Chappe d’Auteroche, Vicente de Doz, and Joaquín Velázquez Cárdenas de León. Introduced and Edited by Doyce N. Nunis, Jr. Translations by James Donahue, Maynard J. Geiger, O.F.M. and Iris Wilson Engstrand. Los Angeles: Natural History Museum of Los Angeles County, 1982. Notes. Bibliography. Illustrations. Index. 185 Pages. $60.00.

Reviewed by Harry W. Crosby, author of Last of the Californios (1981).

Eighteenth-century astronomers anticipated the twice-a-century passage of Venus before the sun as a rare opportunity to make simultaneous observations from many parts of the earth; by timing the transit and comparing data they could calculate the earth’s distance from the sun. Four men, one French, two Spanish and one Mexican, observed the event from points near the tip of the California peninsula and meticulously recorded their findings. Three of these early field scientists had barely arrived after exhausting voyages, found a typhus plague raging at their landfall and were infected and ill during critical days of their work. Two died as an immediate result, but not before making their contributions to this amazing, worldwide, multinational project. The 1769 Transit of Venus carefully presents the story of their preparations, methods, instruments, results, and reproduces their reports. Any student of astronomy or scientific fieldwork should be interested.

From the viewpoint of regional history, the whole affair seems more a colorful sidelight than an integral part of rapidly-changing California in the pivotal year of 1769. Of the scientists, only the Mexican, Velázquez de León, had any local impact. He refined existing knowledge of Antigua California’s latitude and longitude, attempted to improve its mining industry, and made reports on its economic potential that were influential in shaping decision of viceroys and councils for several years. However, Dr. Engstrand’s 1976 work, Royal Officer in Baja California 1768-1770, deals primarily with Velázquez de León and is more complete with respect to his non-astronomical endeavors.

Doyce Nunis, the late Father Maynard Geiger and Iris Engstrand, all have devoted years to creating, largely as labors of love, now-prized works on human activity in the greater Southwest. They and The Natural History Museum of Los Angeles County deserve a salute for this handsomely illustrated and printed reference work on pioneer science in a once-obscure region now grown to be, among other things, a center for gathering data from all corners of the earth and the universe beyond.