WINTHROP, John
Journal of a Voyage to Newfoundland to Observe the Transit of Venus
Boston: Foss and Gill, 1761
First edition.
8vo.
Modern half calf.
WEST, Benjamin
An account of the observations of Venus upon the sun ...
Providence: J Carter, 1769
First edition.
8vo.
Disbound, in a folding case.
The copy of Joseph Brown, with his signature on the titlepage and two holograph corrections in the text.
LEGENTIL (J.G.)
Voyage dans les Mers de L'Inde, fait par ordree du Roi, a l'occasion du Passage de Venus
Paris: L'Imprimerie Royale, 1779-1781
First edition.
Two volumes, large 4to. xx plates.
Contemporary mottled sheepskin.
CHAPPE d'AUTERROCHE, Abbe
Voyage to California to Observe the Transit of Venus
London: Dilly, 1778
First edition in English.
8vo, folding map of Mexico City.
Modern period-style panelled calf.
Twice every 112 - 130 years the planet Venus crosses the disk of the sun - a celestial phenomenon that lasts approximately five hours and is visible to the naked eye. Edmund Halley demonstrated that by measuring the transit time from several locations at widely separated latitudes on the surface of the earth, the distance from the earth to the sun could be determined. This quantity was of such fundamental importance to 18th century scientists that England, France, and the colonists of New England organized scientific expeditions to carry out the observations during the transits of 1761 and 1769. As with solar eclipses, the regions of visibility are limited and change from one transit to the next. The 18th century expeditions were monumental undertakings that lasted months (even years, in the case of Le Gentil) and involved significant hardship, personal risk, and international political friction.
The English colonists in North America shared the enthusiasm for science, philosophy, and culture that characterized the 18th century Enlightenment and were as excited as their European counterparts by the prospect of the Venus transits. John Winthrop was Professor of Astronomy at Harvard when he went to Newfoundland to observe the 1761 transit. This was the first astronomical expedition to be organized and carried out in North America. In 1769, Benjamin West, Joseph Brown, and Stephen Hopkins set up a telescope at the crest of College Hill in Providence RI, at the intersection of two lanes that were subsequently named Transit and Planet Streets. (Stephen Hopkins went on to become governor of Rhode Island and a signer of the Declaration of Independence.) While not an expedition per se, the observations at Providence have the distinction of being, along with those of John Winthrop in Newfoundland and David Rittenhouse in Philadelphia, the only original astronomical observations to be carried out and published in North America prior to 1801 (Early American Imprints, Series I: Evans, 1639 - 1801). The Winthrop and West pamphlets are the only separate astronomy publications; Rittenhouse's observations were published in the Transactions of the American Philosophical Society.
Plan of Mexico City, from Chappe d'Auterroche, Voyage to California to observe the transit of Venus


Guillaume Le Gentil was sent by the Academie to observe the 1761 transit from the French colony at Pondicherry on the southeastern coast of India, but during his voyage war broke out between England and France, the British seized Pondicherry, and he was unable to land. Having missed this opportunity, but unenthusiastic about making the long return home empty-handed, LeGentil spent the next eight years sailing about the Indian Ocean and South Pacific seas while waiting for the 1769 transit. Meanwhile, Pondicherry had been restored to France and as the date of the second transit approached he was able to set up an observatory on land. But on June 3, 1769, the day of the transit, following a month of clear skies, the weather turned cloudy just at the onset of the transit and he was unable to make any observations. The sky cleared again almost immediately afterwards. Despondent, Le Gentil returned to France where, after nine years without word from him, his relations had declared him dead and were in the process of dividing up his estate.
The Abbe Chappe d'Auterroche led an expedition to Siberia for the 1761 transit and a second expedition to Baja California for the transit on June 3, 1769. His journal of the California voyage is a fascinating account of an adventure that began on September 18, 1768, took him from France to Cadiz, across the Atlantic to Vera Cruz, then across the Mexican peninsula and the Gulf of California to his observation point on the Baja peninsula. He describes vividly the nail-biting anxiety while waiting out delays due to miscommunications and diplomatic squabbles between French and Spanish authorities, knowing that his eight month voyage absolutely had to reach its destination by a specific deadline. Along the way he and his colleagues recorded many observations in the jungles of Central America, where few trained European observers had previously explored.
The danger of such an expedition was not lost on M Chappe. On the evening before his departure from Paris, while being counseled not to risk the voyage, he is recorded as remarking "Were I certain that I should die the next morning after I had made my observation, I would not hesitate a moment, nor be in the least deterred from embarking" (quoted in Alexander Chalmer, The General Biographical Dictionary, London 1813).
Chappe d'Auterroche's journal closes on a poignant note. With a few days to spare he reached his observation post, set up his instruments, and on the appointed day made a successful measurement of the transit. The journal ends with the line "At last came the 3rd of June and I had the opportunity of making a most complete observation". Two days later he and most of the other expedition members contracted yellow fever and died. His last recorded words were "I know that I have only a little time left to live, but I have fulfilled my aim and I die content." The two surviving members of the expedition returned to France with the scientific records and Chappe d'Auterroche's journal, which was edited by Cassini de Thury and published posthumously in 1772 as Voyage en Californie pour l'observation du passage de Venus sur le disque du Soleil, le 3 Juin, 1769 . It was translated into English in 1778.