In the Original Printed Boards, Uncut and Unopened
Captain Henry Foster's pendulum experiments, conducted during his 1828-1831 scientific voyage and reported in the Memoirs of the Royal Astronomical Society (1834), were instrumental in refining measurements of Earth's shape. By observing the variation in pendulum oscillations at different latitudes, particularly in the Arctic and South Atlantic, Foster contributed valuable data supporting the hypothesis of Earth's oblate spheroid form. His work helped improve geodetic models and navigation accuracy, advancing early 19th-century geophysical and astronomical science.
There were few officers in the service whose minds could have been more highly cultivated than Foster's," writes one of his comrades in the Arctic expedition (United Service Journal, 1835, pt. ii. pp. 83-4). Foster's notebook, containing all his observations since leaving Porto Bello, was stolen from his body by the canoe-men, but he left an immense mass of observations of various kinds, which the admiralty confided partly to the Royal Society and partly to the Astronomical Society. A report on the pendulum experiments of Foster was drawn up by Francis Baily, the president of the Astronomical Society, and inserted in vol. vii. of their 'Memoirs' - DNB.
Foster drowned in an unfortunate accident in the River Chargres on Feb. 5, 1831, while measuring the difference in Longitude between Panama and Chargres.
Rarity
Rare in commerce, especially in the original printed boards.
Provenance
From the library of Ted Benttinen, with his bookplate laid in.
Henry Foster FRS (1797 – 5 February 1831) was a British naval officer and scientist whose pioneering pendulum experiments advanced the study of Earth's shape and magnetic field. His early career included hydrographic surveys in North and South America, where he collaborated with Basil Hall in measuring Earth's ellipticity using an invariable pendulum. Foster took part in multiple polar expeditions, including Clavering’s 1823 voyage to Greenland and Parry’s 1824–1825 Northwest Passage expedition, where he conducted longitude determinations and geomagnetic observations. His extensive pendulum experiments during these missions earned him the Royal Society’s Copley Medal in 1827. Promoted to commander, Foster led the 1828–1831 British Naval Expedition to the South Atlantic aboard HMS Chanticleer, where he explored the South Shetland Islands, Deception Island, and Cape Horn while continuing geodetic and oceanographic research. His promising career was cut short when he drowned in the Chagres River while conducting astronomical observations in 1831. The results of his pendulum studies were posthumously published in 1834 by Francis Baily, further cementing his legacy in geophysical science.