laboratory built by his widow and surviving children, and at Owens College by an electro-technical laboratory built by his father and other relatives. Hopkinson was a man of most unusual attainments. His great powers as an experimenter in the most difficult fields of scientific research were combined with a wide practical knowledge, and in many of his papers he was able in a quite unique way to employ his high mathematical ability in the solution of practical problems of great commercial importance.
He contributed, as a result of his researches, a great many papers to various learned societies. In the 'Philosophical Transactions of the Royal Society' appeared 'Residual Charge of the Leyden Jar,' 1876-7; 'Refractive Indices of Glass,' 1877; 'Electrostatic Capacity of Glass,' &c., 1877-80-1; 'Torsional Strains in Glass Fibre,' 1878; 'Dielectric Capacity of Liquids,' 1881; 'Magnetisation of Iron,' 1885; 'Dynamo-electric Machinery,' 1886; 'Specific Inductive Capacity,' 1887; 'Magnetic Properties of Impure Nickel,' 1888; 'Magnetic and other Physical Properties of Iron at a high Temperature,' 1889; 'Recalescenceoflron,' 1889; 'Magnetic Properties of Alloys of Nickel and Iron,' 1890; 'Physical Properties of Nickel Steel,' 1890; 'Density of Alloys of Nickel and Iron,' 1891. To 'the ' Philosophical Magazine of the Royal Society' he contributed 'Action of Magnetism on a Permanent Electric Current,' 1880; 'Refractive Index ... of Transparent Insulating Media,' 1882; 'Quadrant Electrometer,' 1885; 'An Unnoticed Danger in Apparatus for Distribution of Electricity,' 1885; 'Seat of Electromotive Forces in a Voltaic Cell,' 1885; and to the 'Messenger of Mathematics :' 'Math. Theory of Tartini's Beats,' 1872; 'Stresses caused by Inequalities of Temperature,' 1879. Among his other papers are ' Group-flashing Lights,' 1874 (Birmingham, 1890); 'Optical Properties of a Titano-silicic Glass ' (Brit. Assoc. 1875); 'Thermo-elastic Properties of Solids,' London, 1887; 'Electric Lighting' (Proc. Inst. Mech. Eng. 1879-80); ' Pres. Address to Junior Engineering Society on Cost of Electric Supply,' 1892; 'Electric Lighthouses of Macquarie and of Tino' ('Proc. Inst. Civil Eng.' vol. lxxxvii.); 'Relation of Mathematics to Engineering' ('Proc. Inst. Civil Eng.' vol. cxviii.) A collected edition of his scientific papers was published in two volumes in 1901 by the Cambridge University Press.
[Obituary notice in Proc. Inst. Civil Engineers, vol. cxxxv.; Royal Society's Cat. of Scientific Papers; private information.]
HORNBY, Sir GEOFFREY THOMAS PHIPPS (1825–1895), admiral of the fleet, second son of Admiral Sir Phipps Hornby [q. v.], was born at Winwick in Lancashire on 20 Feb. 1825. He entered the navy in March 1837 on board the Princess Charlotte, then fitting out as the flagship of Sir Robert Stopford [q.v.] in the Mediterranean. He remained in her till she was paid off in August 1841, and was thus present at all the operations in the Archipelago and on the coast of Syria in 1839 and 1840. (Sir) Phipps Hornby was at this time superintendent of Woolwich dockyard, and the boy remained with him till the spring of 1842, when he was appointed to the Winchester, going out to the Cape of Good Hope as flagship of Rear-admiral Josceline Percy [q. v.] From her, on 15 June 1844, he was promoted to be lieutenant of the Cleopatra, with Captain Christopher Wyvill (1792–1863) [q. v.], for two years' slaver-hunting on the east coast of Africa. In the summer of 1846 he was sent to the Cape in command of a prize, and in the following spring returned to England in the Wolverene. In August his father was appointed commander-in-chief in the Pacific; Hornby went with him as flag-lieutenant, and on 12 Jan. 1850 was promoted to be commander of the flagship Asia of 84 guns. In the summer of 1851 the Asia returned to England, and the admiral settled down at Littlegreen, near Emsworth, a place which he had inherited some fourteen years before, though family arrangements had hitherto prevented his occupying it. Hornby meantime went with his kinsman, Lord Stanley, for a tour in India; but in Ceylon his health broke down, and he was obliged to get home as soon as possible. In the following year his father was a lord of the admiralty in Lord Derby's administration; and on its downfall Hornby was promoted to be captain, 18 Dec. 1852.
Partly, it may be, from political or party reasons, partly because he married in 1853, and in great measure, probably being, by the death of his elder brother, the eldest son to manage his father's property in Sussex, Hornby remained on half-pay till August 1858, when, under Lord Derby's ministry, he was appointed to the Tribune, then in Chinese waters. He joined her at Hongkong in the end of October, and was almost, immediately sent off with a detachment of marines to Vancouver's Island, in consequence of the dispute with the United States relative to San Juan, one of a group of islands between Vancouver's and the mainland. The ownership of the island remained an open question till 1872, when it was