John Caldecott

This idea was aired in 1836, supported by the Resident Colonel James Stuart Fraser and approved by Raja Swathi Thirunal Rama Varma of Travancore.

He was interested in examining the magnetic field of the Earth at various parts, a scheme inspired by Alexander von Humboldt.

Forbes who commented on his observations) to point out errors in the assertions of Professor A. Kupffer, of the Imperial Academy of St. Petersburg who said that the Earth is about 6 degrees cooler than the air (based on measurements in Russia) and pointed out that Bossingault was wrong in assuming that the temperature underground below a depth of one foot was constant.

[3] He made observations on the solar eclipse of 21 December 1843 at Parrat near the origin of the Mahé river and noticed Baily's beads.

[5][6] He also collaborated with Thomas Glanville Taylor of Madras and examined the magnetic field variations in southern India.