John Caldecott also began taking meteorological measurements from July1837 and expanded in 1842 to another building which housed an equatorial circle of Dollond. An Almanac of Travancore was published in 1838. In 1839 Caldecott traveled to Europe to obtain additional instrumentsand Sperschneider headed the observatory during this period. Caldecott died in 1849, and was replaced by John Allan Broun in January 1852. Broun and his helpers like J. Kochukunju, E. In 1874 Kochiravi Pillai helped report the Magnetic Findings of Trivandrum.
The Astronomical Observatory of Thiruvananthapuram is a scientific and astronomical observation station founded in 1837 by the King of Travancore Swathi Thirunal The king wrote to Colonel James Stuart Fraser, the British Resident, an amateur scientist suggesting the creation of an astronomical observatory. That led to the appointment of astronomer John Caldecott, who earlier ran a small personal observatory at Allepey. The observatory was situated at the highest point of the city, opposite the palace, and was considered significant as the magnetic equator passed through Trivandrum at that time. The observatory was designed by Madras Engineers Lieutenant W H Horsley.