An account by Brigade Major William Lambton of the measurement of a base line near Bangalore, together with the particulars of a geographical survey around Mysore. The book is divided into two parts. The first section is comprised of an account of the measurement of the base line near Bangalore and descriptions of the instruments used to determine the latitude and meridian lines for taking the horizontal angles. The second part is an account of the principal operation of the survey, with an explanation of the procedure involved. There are tables for the observations at the latitudes of Seringapatum, Shettagay and Serah, and distances from the meridians of various places, with their deduced latitudes and longitudes.