SKETCH OF SIR WILLIAM THOMSON. 357 



SKETCH OF SIR WILLIAM THOMSON. 



rriHIS distinguished physicist and mathematician was born in Bel- 

 -L fast, in June, 1824. His father, Dr. James Thomson, was a 

 man of large capacity and culture, who studied in the Glasgow Uni- 

 versity, became head-master of the Belfast Academical Institution, 

 and in 1832 was appointed Professor of Mathematics in the University 

 of Glasgow. He made various improvements in mathematics, and 

 wrote books upon education. William passed through the Glasgow 

 University early, and then entei-ed St. Peter's College, Cambridge, 

 from which he graduated as second wrangler in 1845, and he was im- 

 mediately elected Fellow of his college. He afterward went to Paris, 

 and worked in the laboratory of Regnault. In 1846, at the early age 

 of twenty-two, he was appointed Professor of Natural Philosophy in 

 the University of Glasgow, a position which he has filled with dis- 

 tinction, and still occupies. 



Sir William Thomson's earliest contributions to physical science 

 were on the subject of heat, the laws of its motions being treated 

 mathematically. A remarkable paper on "The Uniform Motion of 

 Heat in Homogeneous Solid Bodies," written at the age of seventeen, 

 was full of original conceptions, but it was afterward found that Thom- 

 son had been anticipated in his ideas by Gauss, Chasles, and George 

 Green, of Nottingham. In 1842 he published an important paper on 

 " The Linear Motion of Heat," which contained a method of deriving 

 % geological dates from underground temperatures, a subject which he 

 treated in his inaugural address, in entering upon his professorship 

 at the university. 



It will be impossible here to give any account of the numerous 

 contributions to science made, by Sir William Thomson, as they were 

 generally of so mathematical a cast as to be unintelligible to ordinary 

 readers. His papers on " Electro-Statics " and on " Magnetism " were 

 collected and published in 1872, in a valuable volume of six hundred 

 pages. The more interesting aspects of his work have been well de- 

 scribed by a writer in Nature, and we cannot do better than to quote 

 some passages from his notice : 



"His electrostatic researches led Thomson to the invention of very beautiful 

 instruments for electrostatic measurement. The subject of electrostatic meas- 

 urement occupied much of his attention from the very earliest, when he was 

 obliged to call attention to the defects of the electrometers of Snow Harris. 

 Hi3 labors in this direction have produced the quadrant electrometer, which is 

 employed for all kinds of electric testing in telegraph construction, and for the 

 registration of atmospheric electricity at Kew Observatory ; the portable elec- 

 trometer, for atmospheric electricity and for other purposes, in which the 

 extreme sensitiveness of the quadrant-electrometer is not required ; and the abso- 



