in the mathematical tripos, and in 1856 he obtained a first-class in moral science. He proceeded M.A. in 1858, LL.D. in 1865, and was admitted ad eundem at Durham.
From 1855 to 1861 Hooppell was second and mathematical master at Beaumaris grammar school. He was ordained deacon in 1857, and priest in 1859, and from 1859 to 1861 he served as English chaplain at Menai Bridge. On the foundation at South Shields in 1861 of Dr. Winterbottom's nautical college he was appointed the first head master, and he remained in that position until 1875, when he was instituted to the rectory of Byers Green, co. Durham. For the last year or two of his life he was in delicate health, and wintered at Bournemouth. He died at the Burlington, Oxford Road, in that town on 23 Aug. 1895, and was buried in Bournemouth cemetery. He married at Broxbourne, Hertfordshire, on 20 June 1855, Margaret, daughter of Samuel and Elizabeth Hooppell of Fishleigh, Devonshire; she survived him with two sons and one daughter. Hooppell served on the committee which superintended the excavation of the Roman camp at South Shields. His paper on the discoveries there (Natural History Transactions of Northumberland, vii. 126-42) was the prelude to a lecture, published in 1879, on ' Vinovium, the buried Roman City at Binchester,' between Bishop Auckland and Byers Green, and in 1891 'Vinovia, a buried Roman City,' with thirty-eight illustrations. The substance of this treatise appeared in the journal of the British Archæological Association, and he contributed to the same journal for 1895 a paper on 'Roman Manchester and the Roads to and from it.' From 1877 he read papers on the names of Roman stations before the Newcastle Society of Antiquaries, and he contributed to the 'Archæologia Æliana' and the 'Illustrated Archæologist.' His address, as president of the Tyneside Naturalists' Field Club, is in the 'Natural History Transactions of Northumberland,' vii. 187-206, and after his death there was published in 1898 a volume entitled 'Rambles of an Antiquary,' being a series of papers sent by him to the 'Newcastle Courant' in 1880 and 1881, chiefly on the antiquities of Northumberland and Durham.
Hooppell also published, in addition to several single sermons, 'Reason and Religion, or the leading Doctrines of Christianity,' 1867; 2nd ed. 1895; and 'Materialism, has it any real Foundation in Science?' 2nd ed. 1874.
[Journal Archæol. Assoc. 1895, p. 280; Proc. of Soc. of Antiquaries, Newcastle- upon-Tyne, vii. 134, 141, 145, 156 (with engraved portrait); Newcastle Courant, 31 Aug. 1895, pp. 3, 4; information from R. F. Scoit, esq., bursar, St. John's Coll., Camb., and from Mrs. Hooppell.]
HOPKINSON, JOHN (1849–1898), electrical engineer, eldest son of John Hopkinson, mechanical engineer, was born on 27 July 1849 at Manchester. He was educated under C. Willmore at Queenwood, Hampshire. In 1865 he became a student at Owens College, Manchester, and in 1869 gained a Whitworth scholarship. He studied mathematics under Professor Barker at Owens, and, acting under the professor's advice, entered for and won a minor scholarship at Trinity College, Cambridge, in 1867. At Cambridge he devoted himself to mathematics as his chief study, under Dr. Routh, and in 1871 he became senior wrangler, and subsequently Smith's prizeman. While in residence at Cambridge he proceeded to a degree in science in the university of London (D.Sc. 1871). Shortly after his tripos he was elected a fellow of Trinity College, Cambridge. In 1871 he entered his father's works, and in 1872 he became manager and engineer in the lighthouse and optical department of Messrs* Chance Brothers of Birmingham. In 1874 he invented the group flash system for enabling mariners to distinguish one light from another, the flashes in his system being of varying length and separated by varying intervals of darkness as characterising the lights more distinctly. His great mathematical abilities proved to be of the utmost value to him in this optical work, and later on in his electrical work. His views as to the relation of mathematics to engineering were fully set forth in his 'James Forrest' lecture delivered at the Institution of Civil Engineers in 1894 (Proc. Inst. Civil Engineers, cxviii. 330).
Stimulated by the publication of James Clerk Maxwell's [q.v.] 'Electricity and Magnetism' in 1873, and on the advice of Sir William Thomson (now Lord Kelvin), he carried out in 1876-7 a valuable series of experiments on the residual charge of the Leyden jar, and on the electrostatic capacity of glass. The results of these researches were published in four papers in the 'Philosophical Transactions' of the Royal Society (1876-1881), and he worked continuously on this subject almost up to the time of his death, the last paper he published on the question being one on 'The Capacity and Residual Charge of Dielectrics as affected by Temperature and Time' (Phil. Trans. 1897).
In 1878 he resigned his post with Messrs. Chance Brothers and set up as a consulting