NOTICE BY PROF. J. LOVEEING. 431 



even begin his apprenticeship. He pursued his studies to the verge 

 of starvation; his heated brain worked while his body shivered 

 before a fireless stove, often covered with ice. His book, which 

 placed him before his death, in 1854, among the greatest of Ger- 

 man physicists, was coldly received by his colleagues in the College 

 of Jesuits, at Cologne. On the contrary, Professor Henry's recog- 

 nition was prompt and sympathetic, at home and abroad ; at a single 

 bound he came to the front, and there he always remained. 



In 1832, Professor Henry removed to Princeton to fill the chair 

 of Natural Philosophy in the College of New Jersey. Here he 

 found sympathizing associates, congenial duties, and the opportunity 

 for original research. One year earlier Faraday, already widely 

 known by his chemical discoveries, appeared upon the field of 

 experimental electricity, and immediately became the most conspicu- 

 ous figure thereon, the cynosure of admiring eyes in every land. 

 His discovery of induced currents, and of the evolution of elec- 

 tricity from magnets, marked a new era in the science of electricity, 

 elucidating facts which had defied the ingenuity of Arago, Herschel, 

 and Babbage, creating the science of magneto-electricity as the cor- 

 relative of electro-magnetism, and justly claiming for its last-born 

 the splendors and wonders of the Ruhmkorff coil, the Gramme 

 machine, and the telephone. Henry supplemented the work of 

 Faraday by his own discoveries of the extra-current in the primi- 

 tive circuit, and of induced currents of higher orders in as many 

 adjacent circuits. He also succeeded where Faraday had doubts 

 about his own experiments; viz: in obtaining unequivocal indica- 

 tions of similar induction in the momentary passage of electricity 

 of high tension ; proving also the oscillating discharge of the Ley- 

 den jar. Numerous experiments were made on induction by thun- 

 der-clouds, and on atmospheric electricity in general, by means of 

 tandem-kites and lightning-rods. 



Nobili and Melloni had widened and deepened the foundations 

 of thermotics, unveiling new and intimate analogies between radiant 

 light and heat, and enriching physical cabinets with many novelties, 

 especially the thermopile and the galvanometer. Henry took advan- 

 tage of the new instruments for measuring the heat of different 

 parts of the sun. Secchi, the late astronomer and meteorologist of 



