HARRIS, SIR WILLIAM SNOW (1791-1867), a distinguished electrician, was descended from an old family of Plymouth solicitors, and was born there 1st April 1791. He received his early education at the Plymouth grammar-school, and completed a course of medical studies at the university of Edinburgh, after which he established himself as a general medical practitioner in Plymouth. On his marriage in 1824 he resolved to abandon his profession on account of its duties interfering too much with his favourite study of electricity. As early as 1820 he had invented a new method of arranging the lightning conductors of ships, the peculiarity of which was that the metal 1-as permanently fixed in the masts and extended throughout the hull; but it was only with great difficulty, and not till nearly thirty years afterwards, that his invention was adopted by the Government for the royal navy. In 1826 lie read a paper before the Royal Society "On the Relative Powers of various Metallic Substances as Conductors of Electricity," which led to his being elected a member of the society- in 1831. Subsequently, in 1831, 1836, and 1839, he read before the society several valuable papers on the elementary laws of electricity, and he also communicated to the Royal Society of Edinburgh various interesting accounts of his experiments and discoveries in the same field of inquiry. In 1835 he received the Copley gold medal from the Royal Society for his papers on the " Laws of Electricity by High Tension," and in 1839 he was chosen to deliver the Bakerian lecture. Meanwhile, although a Government commission had recommended the general adoption of his conductors in the royal navy, and the Government had granted him an annuity of £300 " in consideration of services in the cultivation of science," the naval authorities continued to offer various objections to his invention ; to aid in removing these he in 1813 published his work on Thunderstorms, and also about the same time contributed a number of papers to the Yautical Magazine illustrative of damage by lightning. His system was actually adopted in the Russian navy before he succeeded in removing the prejudices against it in England, and in 1845 the emperor of Russia in acknowledgment of his services presented him with a valuable ring and a superb vase. At length, every doubt as to the efficiency of his system having been removed, he received in 1817 the honour of knighthood, and subsequently a grant of £5000. After succeeding in introducing his invention into general use Harris resumed his labours in the field of original research, but as he failed to realize the advances that had been made by the new school of science his application resulted in no discoveries of much value. His manuals of Electricity, Galvanism, and Magnetism, contributed to Weale's rudimentary series, were however written with great clearness, and passed through several editions. He died 22d January 1867, while having in preparation a Treatise on Frictional Electricity, which was published posthumously in the same year, with a memoir of the author by Charles Tomlinson, F.R.S.