In John Keay's The Great Arc, readers embark on a captivating journey through 19th-century India, following the remarkable story of the Great Trigonometrical Survey of India. This non-fiction narrative unravels the ambitious project to measure and map the subcontinent with unprecedented precision, led by the brilliant figures of William Lambton and George Everest. Against the backdrop of British colonialism in India, Keay's narrative blends adventure, exploration, and cultural clashes, offering a compelling account of the survey's significance. The Great Arc is a captivating exploration of science, empire, and the enthralling history of cartography, making it an essential read for history enthusiasts.