BIOGRAPHICAL SKETCH 



attraction for himself. In Heat as a 

 Mode of Motion (see p. 12), which has 

 been regarded as the best of Tyndall's 

 books, that difficult subject was for the 

 first time presented in a popular form. 

 The book on Light gives the substance 

 of lectures delivered in the United 

 States in the winter of 1872-3. The 

 proceeds of these lectures, which by 

 judicious investment amounted in a few 

 years to between ^6,000 and .7,000, 

 were devoted to the encouragement of 

 science in the United States. 



His views upon the great question as 

 to the relation between science and 

 theological opinions are best given in his 

 presidential address to the British Asso- 

 ciation at Belfast in 1874, which occa- 

 sioned much controversy at the time 

 (reprinted, with essays on kindred sub- 

 jects, in Fragments of Science, vol. ii.). 

 The main purpose of that address was 

 to maintain the claims of science to 

 discuss all such questions fully and 

 freely in all their bearings. 



On February 2 gth, 1876, Tyndall mar- 

 ried Louisa, eldest daughter of Lord 

 Claud Hamilton, who became his com- 

 panion in all things. In 1877 they built 

 a cottage at Bel Alp, on the northern 

 side of the Valaise, above Brieg. There 

 they spent their summers amid his 

 favourite haunts. In 1885 they built 

 what Tyndall called "a retreat for his 

 old age" upon the summit of Hind 

 Head, on the Surrey moors, then a very 

 retired district. Sleeplessness and weak- 

 ness of digestion ills from which he 

 had suffered more or less all his life 

 increased upon him in later years, and 

 caused him to resign his post at the 

 Royal Institution in March, 1887. His 

 later years were for the most part spent 

 at Hind Head. Repeated attacks of 

 severe illness, unhappily, prevented the 



execution of the many plans he had laid 

 out for his years of retirement. In 1893 

 he returned greatly benefited from a 

 three months' sojourn in the Alps. But 

 a dose of chloral, accidentally adminis- 

 tered, brought all to a close on December 

 4th, 1893. 



Tyndall's single-hearted devotion to 

 science and indifference to worldly advan- 

 tages were but one manifestation of a noble 

 and generous nature. A resolute will 

 and lofty principles, always pointing to a 

 high ideal, were in him associated with 

 great tenderness and consideration for 

 others. His chivalrous sense of justice 

 led him not unfrequently irrespective 

 of nationality or even of personal ac- 

 quaintance, and often at great cost of 

 time and trouble to himself to take up 

 the cause of men whom he deemed to 

 have been unfairly treated or overlooked 

 in respect to their scientific merits. He 

 thus vindicated the claim of the unfortu- 

 nate German physician, Dr. Julius 

 Robert Mayer, to have been the first to 

 lay down clearly the principle of the 

 conservation of energy and to point out 

 its universal application ; and succeeded 

 in obtaining his recognition by the 

 scientific world in spite of eminent 

 opposition. The same spirit appeared 

 in his defence of Rendu's title to a share 

 in the explanation of glacier movement, 

 and of Wigham's services in regard to 

 lighthouses. 



Tyndall took a warm interest in some 

 great political questions. He sided 

 strongly with the Liberal Unionists in 

 opposing Mr. Gladstone's Home Rule 

 policy. 



Tyndall was of middle height, sparely 

 built, but with a strength, toughness, and 

 flexibility of limb which qualified him 

 to endure great fatigue and achieve the 



