Page:Dictionary of National Biography volume 54.djvu/262

 a visit to Paris and a walk over the Field of Waterloo in the summer of 1816.’ This work was dedicated to the Society of United Friars of Norwich, a literary society of which he was almost the last survivor. In 1827 he published in two volumes ‘A Tour in France, Savoy, Northern Italy, Switzerland, Germany, and the Netherlands,’ and in the same year was elected a fellow of the Society of Antiquaries. In 1828 he was nominated a sheriff of the city of Norwich, became an alderman in the same year, and served the office of mayor in 1832. He was elected an associate of the British Archæological Association in 1845, and on the establishment of the Numismatic Society in 1836 he became a member. For many years all his leisure time was engaged in composing a complete dictionary of Roman coins. His idea was to give an explanation of the types, symbols, and devices on consular and imperial coins, biographical notices of the emperors from Julius to Mauricius, and mythological, historical, and geographical notices in elucidation of rare coins. This work, with illustrations by [q. v.], was left incomplete at the time of his death, as to the last letters U to Z. It was then revised in part by [q. v.], and, being completed by Frederic William Madden, was published, after many delays, in 1889 under the title of ‘A Dictionary of Roman Coins, Republican and Imperial,’ and remains the standard work on the subject. Stevenson died at Cambridge on 22 Dec. 1853, in the house of his son-in-law, John Deighton, surgeon.

By his wife Mary, he had two sons, of whom Mr. Henry Stevenson, F.L.S., is author of ‘The Birds of Norfolk’ (1866–90, 3 vols. 8vo).



STEVENSON, THOMAS (1818–1887), engineer and meteorologist, born in Edinburgh on 22 July 1818, was youngest son of [q. v.], and was brother of [q. v.], and of [q. v.] He was educated at the high school of Edinburgh where he showed an incapacity for arithmetical calculation which remained with him through life. His mathematical faculty was, however, above the average, and he acquired a knowledge of Latin which he cultivated in later years, Lactantius, Lucan, Vossius, and Cardinal Bona becoming favourite authors. In youth he formed an ardent love of the English classics, and soon developed the habits of a book collector and the faculty of writing English with grace, vigour, and distinction.

In his seventeenth year Stevenson entered his father's office with a view to becoming an engineer. When his apprenticeship was over he in 1842 wrote a paper on the defects of the rain-gauges then in use, with a description of one of an improved form. This was published in the ‘Edinburgh New Philosophical Journal,’ 1842, xxxiii. 12–21, and was the first of a series of numerous contributions to scientific journals on such subjects as lighthouse and harbour engineering, lighthouse optics, experiments on the force of waves, and meteorology. By 1883 these papers had reached a total of forty-four (see Royal Society's Cat. of Scientific Papers, 1800–63 p. 829, 1864–73 pp. 1014–15, and 1874–83 pp. 495–6). In 1843 Stevenson superintended the construction of the lighthouse on Little Ross Island on the Solway, and wrote a paper on the geology of the island (Edinb. New Phil. Journ. xxxv. 83–8). In 1846 he became a partner in his father's firm, and in 1853 he and his brother David were appointed engineers to the board of northern lighthouses. This position he held till his health failed in 1885.

Stevenson won his chief reputation by his successful pursuit of the experiments in lighthouse illumination, which his brother, Alan Stevenson, began. By his efforts ‘the great sea lights in every quarter of the world now shine more brightly.’ His crowning invention was his ‘azimuthal condensing system of lighthouse illumination.’ No attempt had previously been made to allocate the auxiliary light in proportion to the varying lengths of the different ranges and the amplitudes of the arcs to be illuminated, or, where a light had to show all round the horizon, to weaken its intensity in one arc, and with the rays so abstracted to strengthen some other arc, which from its range being longer required to be of greater power. To perfecting this invention he devoted the greater part of his time from 1855 to 1885. Other inventions and improvements he described in his ‘Lighthouse Illumination,’ 1859 (2nd ed. 1871, expanded into ‘Lighthouse Construction and Illumination,’ 1881; see, Reply to Messrs. D. and T. Stevenson's Pamphlet on Lighthouses, 1860), and in his article ‘Lighthouse’ in the ninth edition of the ‘Encyclopædia Britannica.’

Other separately issued works were: ‘Design and Construction of Harbours,’ 1864, Edinburgh (2nd ed. 1874; 3rd ed. 1886), a