1816, and devoted himself to his favourite studies—astronomy, terrestrial magnetism, and ornithology—under the supervision of his brother-in-law, Henry Browne, F.R.S., at whose house (2 Portland Place, London) he met Captain Henry Kater, F.R.S., and other kindred spirits.
Sabine was elected a fellow of the Royal Society in 1818, and the same year, on the recommendation of the president and council, he was appointed astronomer to the arctic expedition in search of a north-west passage, which sailed in the Isabella under Commander (afterwards Sir) John Ross (1777–1856) [q. v.] and was absent from May to November. His report on the biological results of the expedition appeared in the ‘Transactions of the Linnean Society,’ vol. xii., and embraced twenty-four species of birds from Greenland, of which four were new to the list, and one, the Larus Sabini, entirely new. He further contributed an account of the Esquimaux of the west coast of Greenland to the ‘Quarterly Journal of Science,’ 1819.
Sabine accompanied, in a similar capacity, a second arctic expedition in 1819, which sailed in the Hecla under Lieutenant-commander (afterwards Sir) Edward Parry [q. v.], and was away from May 1819 until November 1820. He tabulated all the observations, and arranged nearly all the appendix of Parry's journal, and Parry warmly acknowledged his valuable assistance throughout the expedition. During the tedious stay for the winter months in Winter Harbour, when the sun was ninety-six days below the horizon, Sabine edited a weekly journal for the amusement of the party, which was entitled ‘The North Georgia Gazette and Winter Chronicle,’ and extended to twenty-one numbers. In 1821 he received the Copley medal of the Royal Society for various communications relating to his researches during the arctic expedition.
Sabine was next selected to conduct a series of experiments for determining the variation in different latitudes in the length of the pendulum vibrating seconds, with a view to ascertain the true figure of the earth, a subject which had engaged his attention in the first arctic voyage. He sailed in the Pheasant on 12 Nov. 1821, and returned on 5 Jan. 1823, having visited St. Thomas (Gulf of Guinea), Maranham, Ascension, Sierra Leone, Trinidad, Bahia, and Jamaica. On 1 May 1823 he sailed in the Griper on the same duty, returning on 19 Dec., having visited New York, Trondhjem, Hammerfest, Greenland, and Spitzbergen.
Sabine's observations of the magnetic inclination and force at St. Thomas in 1822 were the first made on that island. Utilised as a base of comparison with later observations of the Portuguese, they are important as showing the remarkable secular change which was in progress during the interval. The account of Sabine's pendulum experiments, printed in a quarto volume by the board of longitude in 1825, is an enduring monument of his indefatigable industry, his spirit of inquiry, and wide range of observation. The work was honoured by the award to him of the Lalande gold medal of the Institute of France in 1826.
In 1825 Sabine was appointed a joint commissioner with Sir John Herschel to act with a French government commission in determining the precise difference of longitude between the observatories of Paris and Greenwich by means of rocket-signals. The difference of longitude thus found was nine minutes 21.6 seconds. The accepted difference at the present time, by electric signalling, is nine minutes twenty-one seconds. On 31 Dec. 1827 Sabine was promoted first captain, and having obtained from the Duke of Wellington, then master-general of the ordnance, general leave of absence so long as he was not required for military service, and on the understanding that he was usefully employed in scientific pursuits, he acted until 1829 as one of the secretaries of the Royal Society.
In 1827 and the two following years Sabine made experiments to determine the relative lengths of the seconds pendulum in Paris, London, Greenwich, and Altona, and he afterwards determined the absolute length at Greenwich. On the abolition of the board of longitude in 1828, it was arranged that three scientific advisers of the admiralty should be nominated, the selection being limited to the council of the Royal Society. Sabine, Faraday, and Young were appointed. Sabine's appointment was violently attacked by Charles Babbage in a pamphlet generally denouncing the Royal Society, entitled ‘Reflections on the Decline of Science in England, and on some of its Causes’ (1830). Sabine did not answer Babbage's unmannerly attack, but contented himself with inserting in the ‘Philosophical Magazine’ for 1830 an explanation on one point upon which particular stress had been laid.
The condition of Ireland in 1830 necessitated an increased military establishment, and Sabine was recalled to military duty in that country, where he served for seven years. During this time he continued his pendulum investigations, and in 1834 commenced, in conjunction with Professor Humphrey Lloyd, afterwards provost of Trinity
