ELI AS LOOMIS. 325 



Dulong, Pouillet, and others. In the autumn of 1837 he began his 

 labors at Iludsou. Here he remained for seven years, maintaining 

 ■with unflagging perseverance both his work in teaching and his scien- 

 tific labors. 



In 1844 he was offered, and he accepted, the office of Professor of 

 Mathematics and Natural Philosophy in the University of New York. 



When Professor Henry resigned his professorship at Princeton iu 

 order to accept the office of Secretary of the Smithsonian Institution, 

 Professor Loomis was offered the vacant chair. He went to Princeton 

 and remained there one year, at the end of which he was induced 

 to return again to New York. Here he continued until 1860, when 

 he was elected to the professorship in Yale College made vacant by 

 the death of Professor Olmsted. For the last twenty-nine years of 

 his life he there labored for the College and for science, passing away 

 on the loth of August, 1889. 



There are three or four lines of the scientific activity of our late 

 Associate sufficiently distinct to be considered separately, without 

 strict regard to chronology. 



Terrestrial Magnetism and the Aurora. — A subject of which he 

 early undertook the investigation was Terrestrial Magnetism. The 

 daily motions of the magnetic needle were those which Tutor Loomis 

 first studied. At the beginning of the second year of his tutorship, 

 he set up by the north window of his college room a heavy wooden 

 block, and on it the variation compass belonging to the College. Here 

 for thirteen months he observed the position of the needle at hourly 

 intervals in the daytime, his observations usually being for seventeen 

 successive hours of each day. The results of these observations, 

 together with a special discussion of the extraordinary cases of dis- 

 turbance, were published in the American Journal of Science in 1836. 

 No similar observations of the kind made in this country had at that 

 time been published, and it is believed that there are only one or two 

 like series of hourly observations made in Europe earlier than these 

 by Tutor Loomis. He also at this time formed the purpose of col- 

 lecting all the observations of magnetic declination that had hitherto 

 been made in the United States. From these he constructed a mag- 

 netic chart of the country. These were the first published magnetic 

 charts of the United States. In the following years he made numer- 

 ous observations of the magnetic dip at widely distributed stations in 

 the United States, — observations which are of great value in pres- 

 ent discussions of the changes of the magnetic elements. 



Closely connected with terrestrial magnetism, and to be considered 



