Report of the Length of the Pendulum at the Equator, from Experiments and Observations made on an Expedition fitted out under his direction from the Observatory at Madras; by the order of the Madras Government in the Year 1821, together with a deduction of the Figure of the Earth by combining the Equator, Madras and London, Experiments, also the Geographical Situation of Different Places seen on the Expedition with Plans and Views