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.