Account of the Operations of the Great Trigonometrical Survey of India: Details of the principal triangulation of eleven of the component series of the North-East quadrilateral, including the following series : the Gurwani meridional, the Gora meridional, the Hurilaong meridional, the Chendwar meridional, the North Parasnath meridional, the North Maluncha meridional, the Calcutta meridional, the East Calcutta longitudinal, the Brahmaputra meridional, the Eastern frontier, sec. 23° to 26°, the Assam longitudinal (1882) PDF Download