XIX 



required security at all times, and under all the variable circumstances in 

 ■which the ship might be placed. 



In 1824 Harris married the eldest daughter of Richard Thorne, Esq., 

 of Pilton, North Devon, and from this time he chiefly devoted himself to 

 the cultivation of electrical science. The earlier results of his study at this 

 period were for the most part laid before the Royal Society of Edinburgh 

 in a series of papers, the first of v^hich, entitled "Experimental Inqui- 

 ries concerning the Lav^'S of Magnetic Forces," appeared in the * Trans- 

 actions ' in 1829 ; but the paper is dated Plymouth, July 1, 1827. It 

 contains an account of the hydrostatic magnetometer. The second 

 paper, On a new Electrometer, and the heat excited in metallic bodies 

 by Yohaic Electricity," is dated May 5th, 1831. The third paper, dated 

 xlpril 5th, 1833, is On the Investigation of Magnetic Intensity by the 

 Oscillations of the Horizontal Needle." By this time the author had been 

 elected a Fellow of both the London and Edinburgh Royal Societies. 



The bent of Harris's mind for improving and constructing electrical 

 instruments is shown at this early period. Indeed his connexion with the 

 Royal Society was in a great measure due to this cause. The President, 

 Sir Humphry Davy, having been attracted by his electrical thermometer, 

 invited him to give an account of it to the Society, which he did in 1826 ; 

 and his first paper appeared in the Philosophical Transactions under the 

 following title: "On the relative powers of various metallic substances 

 as conductors of Electricity." 



Harris's researches on some of the elementary laws of electricity ap- 

 peared in the Philosophical Transactions in 1834, 1836, and 1839, and 

 they display in a striking manner the author's ingenuity and delicate mani- 

 pulative skill. He was not satisfied with the attainment of his end by 

 auT/ means, but the means themselves were the subject of long and patient 

 thought and repeated trials, until the best means possible under the cir- 

 cumstances had been hit upon. This care in the selection and improve- 

 ment of apparatus might seem to an ordinary observer to be often super- 

 fluous, but it led to success, and to the thorough understanding of the 

 conditions of success; so that the ultimate failure of an experiment in 

 Harris's hands became next to impossible. But with all this love of ap- 

 paratus, and of its minute details, Harris had none of the spirit of a mere 

 mechanical artist ; he knew that the best instrument does the best work 

 only under the guidance of the best mind. But Harris's ingenuity was by 

 no means confined to his apparatus. There was not a room in his house, 

 from the attic to the kitchen, that did not bear marks of an original mind. 

 He converted the ceiling of his children's nursery into a planetarium, and 

 the floor into a compass card. He did not disdain to invent a child's toy, 

 or to rectify a defect in his ingenious kitchen range. 



In 1835 the Copley Medal, the "olive crown" of the Royal Society, as 

 Davy loved to call it, was bestowed on Harris in recognition of the value 

 of his papers on the laws of electricity of high tension. In 1839 his 



c 2 



