THE GREAT ARC

A technically dense but readable and ultimately fascinating account of the star-crossed Great Indian Arc mapping project, which consumed 50 years and scores of lives in a quintessentially British attempt to survey the Indian subcontinent—a tale that offers wry insights regarding imperialism and scientific caprice.

Keay supplements his recent, definitive India: A History (p. 42) with a slim yet sweeping volume documenting the deceptively reasonable aims of the Survey and the eccentric British civil servants who doggedly advanced it in the face of ridiculous obstacles—ranging from tiger attacks to brutal maladies like malaria. Keay offers telling portraits of the two expedition chiefs. First, the indefatigable, bohemian William Lambton, who first envisioned using the navigational technique of triangulation to both plot the subcontinent and measure the earth’s arc itself, and who termed his decades in India (with his wife and growing family) the happiest of his life. He was followed by George Everest, eventual namesake of the Himalayan peak, a humorless perfectionist given to withering tirades against his loyal staff (“You all seem to me to be right stark staring mad”). While Lambton commenced the Great Trigonometrical Survey in 1803, Everest proved to have the qualities necessary to finish such a bizarre task, which required carrying along precision instruments (primarily the Great Theodolite, a delicate, sextant-like device weighing a half-ton) through remote jungle and up mountains, then waiting for the construction of distant towers upon which to take triangulation readings. In the final irony, although the survey was acclaimed and pondered in England during its 50-year duration, rapid scientific and political developments (including the mid-19th–century Indian uprising against the British, partially inspired by the Survey’s invasive tactics) soon banished it from public memory.

In a manner reminiscent of T. Corraghessan Boyle’s historical fiction, Keay captures—with clarity, dry humor, and attention to historic and scientific arcane—the driven spirit and outsized dreams of Lambton, Everest, and the administrative impulses that simultaneously elevated and doomed the colonialist era.