PHYSICS OF NINETEENTH CENT. RADIATION. 511 



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of Switzerland in 1856; and they afterwards published a joint paper 

 on the structure and motion of glaciers. He r-eturned to Switzerland 

 in 1857, 1858, and 1859, and pursued his mY^tigations^^eaching^ I> 

 Chamouni on Christmas night, 1859, through deep snow, and two 

 days afterwards succeeded in attaining the Montanvert, where he re- 

 mained nearly three days, for the most part amid blinding snow, and 

 determined the winter motion of the Mer de Glace. In i&5# be 

 commenced his researches on radiant heat, which have disclosed 

 relations previously unthought of between this agent and the gaseous 

 form of matter. Numerous memoirs published in the 'Philosophical 

 Transactions ' are devoted to this subject. In one of them a ray-filter 

 is described, by means of which the luminous rays of the sun, the 

 electric light, and the limelight are detached from the non-luminous 

 ones, combustion and vivid incandescence being effected at foci ab- 

 solutely dark. Mr. Tyndall is a Rumford Medallist of the Royal 

 Society, and a member of various foreign scientific societies ; he was 

 made LL.D. of Cambridge in 1855, and LL.D. of Edinburgh in 1866, 

 when Mr. Carlyle was installed Rector of the University. In 1872 

 Professor Tyndall went on a lecturing tour in the United States ; in 

 the course of it he delivered thirty-five lectures, which returned him 

 $23,100. After paying expenses, a fund of over $13,000 remained, 

 and this, before leaving for Europe, the professor placed in the hands 

 of a committee, who were authorized ' to expend the interest in aid 

 of students who devote themselves to original research.' On the 

 occasion of his receiving the honorary degree of D.C.L. from the 

 University of Oxford, June 18, 1873, Dr. Heurtley, Margaret Professor 

 of Divinity, protested against the proceeding, on the ground that 

 Professor Tyndall ' had signalized himself by writing against and de- 

 nying the credibility of miracles and the efficacy of prayer, thus con- 

 travening the whole tenour of that book, which, with its open page, 

 inscribed " Dominus Illuminatio mea," the University still bears as 

 her device, and therefore still professes to acknowledge as her guide.' 

 Professor Tyndall presided at the annual meeting of the British As- 

 sociation held at Belfast in August, 1874. He accepted the presi- 

 dency of the Birmingham and Midland Institute for the year 1877. 

 He has written the 'Glaciers of the Alps,' 1860; 'Mountaineering/ 

 1861 ; 'A Vacation Tour/ 1862; 'Heat considered as a Mode of 

 Motion/ 1863 ; ' On Radiation : the " Rede " Lecture, May 16, 1865,' 

 published in 1865 ; a volume on ' Sound ; ' ' Faraday as a Discoverer;' 

 'Fragments of Science;' 'Notes on Electricity/ 1870; 'Notes on 

 Light/ 1871 ; ' Hours of Exercise in the Alps/ 1871 ; ' The Forms of 

 Water in Clouds and Rivers, Ice and Glaciers/ 1872 : 'Address de- 

 livered before the British Association assembled at Belfast, with Ad- 

 ' ditions and a Preface/ 1874 ; and ' Fragments of Science/ 1876. He 

 married, February 29, 1876, Louisa Claud Hamilton, eldest daughter 

 of Lord and Lady Claud Hamilton"." 



