The earliest items are two books of mathematical theorems, 1811 and 1813. There are volumes of notes and observations for both Fisher's Arctic voyages and for his period in the Mediterranean, accounts of later scientific work and abstracts of observations made by other scientists. This is the material which formed the basis of the scientific papers which he published in the Philosophical Transactions and elsewhere. There are letterbooks for Greenwich Hospital School from 1836 to 1863 (excepting the years 1858, 1859 and 1860) and other reports and papers relating to the School There are a number of items collected by Fisher. The most important are Peter Puget's journal for March to May 1793 in the Chatham, storeship for Vancouver's expedition; a meteorological log also giving details of ship arrivals and departures at Madras, 1815 to 1816; Franklin's (q.v.) lunar observations on board the Trent in 1818 and Parry's (1790-1855) meteorological journal on his first two voyages in search of the North-West Passage in 1819 to 1820 and 1821 to 1823. Fisher's scientific instruments were presented to the Museum in 1958 and are held in the Navigation Department.

Administrative / biographical background
Owing to the death of his father, Fisher had to go out to work at an early age. However, his interest in science won him recognition and in 1817 he was able to go to Cambridge University. In 1818 he sailed as astronomer with the naval expedition to Spitsbergen commanded by Captain David Buchan (d. ca. 1839) in the Dorothea and the Trent. He then returned to Cambridge. In 1821 he graduated and was ordained. In that year he sailed with Captain W.E. Parry (1790-1855), on his second expedition, 1821 to 1823, to search for the North-West Passage, in the double capacity of chaplain and astronomer. During both these expeditions he made astronomical and magnetic observations and did some pioneer work on the physical, chemical and physiological consequences of the Arctic climate. In recognition of his work he was elected a Fellow of the Royal Society in 1825. From 1828 to 1832 he served in the Mediterranean as chaplain in the Spartiate and Asia and continued his work on astronomy and magnetism. From 1834 to 1863 Fisher was Headmaster of the Greenwich Hospital School, where he continued his scientific work and established an observatory.