Dictionary of National Biography, 1885-1900/Dodson, James

DODSON, JAMES (d. 1757), teacher of the mathematics and master of the Royal Mathematical School, Christ's Hospital, is known chiefly by his work on 'The Anti-Logarithmic Canon' and 'The Mathematical Miscellany.' Of his early life nothing is known, except that his contemporary, Dr. Matthew Maty, in his 'Mémoire sur la vie et sur les écrits de M. A. de Moivre,' enumerated Dodson among 'les disciples qu'il a formés.' In 1742 Dodson published his most important work, 'The Anti-Logarithmic Canon. Being a table of numbers consisting of eleven places of figures, corresponding to all Logarithms under 100,000, with an Introduction containing a short account of Logarithms.' This was unique until 1849. The canon had been actually calculated, it is asserted, by Walter Warner and John Pell, about 1630-40, and Warner had left it to Dr. H. Thorndyke, at whose death it came to Dr. Busby of Westminster [q. v.], and finally was bought for the Royal Society; but for some years it has been lost. From a letter of Pell's, 7 Aug. 1644, written to Sir Charles Cavendish, we find that Warner became bankrupt, and Pell surmises that the manuscript would be destroyed by the creditors in ignorance. In 1747 Dodson published 'The Calculator . . . adapted to Science, Business, and Pleasure.' It is a large collection of small tables, with sufficient, though not the most convenient, seven-figure logarithms. This he dedicated to William Jones. The same year he commenced the publication of 'The Mathematical Miscellany,' containing analytical and algebraical solutions of a large number of problems in various branches of mathematics. His preface to vol. i. is dated 14 Jan. 1747, the title giving 1748. This volume is dedicated to A. de Moivre, and a second edition was issued by his publisher in 1775. Vol. ii. (1753) is dedicated to David Papillon, and contains a contribution by A. de Moivre. Vol. iii. (1755) he dedicated ‘to the Right Hon. George, Earl of Macclesfield, President, the Council, and the rest of the Fellows of the Royal Society.’ This volume is devoted to problems relating to annuities, reversions, insurances, leases on lives, &c., subjects to which Dodson devoted special attention. His ‘Accountant, or a Method of Book-keeping,’ was published 1750, with a dedication to Lord Macclesfield. In 1751 he edited Wingate's ‘Arithmetic,’ which had previously been edited by John Kersey and afterwards by George Shelley. Dodson's edition is considered the best. Another work, ‘An Account of the Methods used to describe Lines on Dr. Halley's Chart of the terraqueous Globe, showing the variation of the magnetic needle about the year 1756 in all the known seas, &c. By Wm. Mountaine and James Dodson,’ was published in 1758, after Dodson's death.

He was elected a fellow of the Royal Society 16 Jan. 1755, and was admitted 23 Jan. 1755, probably on the merits of his published works, with the patronage of his friend, Lord Macclesfield, who not long before was elected president of the society. On 7 Aug. of the same year he was elected master of the Royal Mathematical School, Christ's Hospital, which post he held until his death. Before his election to this mastership he seems to have been an ‘accomptant and teacher of the mathematics.’

Having been refused admission to the Amicable Life Assurance Society, because they admitted none over forty-five years of age, he determined to form a new society upon a plan of assurance more equitable than that of the Amicable Society. After Dodson's vain attempts to procure a charter from 1756 to 1761, the scheme was taken in hand by Edward Rowe Mores and others, who by deed in 1762—the year following Dodson's death—started the society now known as the Equitable Society.

Dodson died 23 Nov. 1757, being over forty-seven years of age. He lived at Bell Dock, Wapping. His children were left ill provided for. At a meeting of the general court holden in Christ's Hospital 15 Dec. 1757 a petition was read from Mr. William Mountaine, where it was stated that Dodson died ‘in very mean circumstances, leaving three motherless children unprovided for, viz. James, aged 15, Thomas, aged 11 and three quarters, and Elizabeth, aged 8.’ The two youngest were admitted into the hospital. After the Equitable Society had started, and fifteen years or more after Dodson's death, a resolution was put in the minutes for giving 300l. to the children of Dodson, as a recompense for the ‘Tables of Lives’ which their father had prepared for the society. Dodson's eldest son, James the younger, succeeded to the actuaryship of the society in 1764, but in 1767 left for the custom house.

Augustus De Morgan [q. v.] was the great-grandson of Dodson, his mother being the daughter of James Dodson the younger. In De Morgan's ‘Life’ is the following: ‘But he was mathematical master at Christ's Hospital, and some of his descendants seem to have thought this a blot on the scutcheon, for his great-grandson has left on record the impression he had of his ancestor. When quite a boy he asked one of his aunts “who James Dodson was,” and received for answer, “We never cry stinking fish.” So he was afraid to ask any more questions, but settled that somehow or other James Dodson was the “stinking fish” of his family; but he had to wait a few years to find out that his great-grandfather was the only one of his ancestors whose name would be deserving of mention.’

[C. Hutton's Dictionary, 1815; Memoir by Nicollet in the Biographie Universelle; A. de Morgan's Life by his wife, 1882; F. Bailey's Account of Life Assurance Companies, 1810; Nichols's Literary Anecdotes, vol. v. 1812; information supplied by M. S. S. Dipnall, and original manuscript collections by A. De Morgan, communicated by his son, Wm. De Morgan; and the books mentioned.]

G. J. G.