I20 The Smithsoman Institution 



intelligent and liberal, and all gates were open to a young 

 man of integrity and enterprise. 



He now entered upon serious work — first as a pupil in a 

 night school ; then in the Albany Academy, as scholar and 

 teacher ; later as a medical student, a private tutor, and a 

 surveyor. At the age of twenty-six he was appointed Pro- 

 fessor of Mathematics in the Albany Academy, and his 

 scientific life was fairly begun. 



His famous paper in Silliman's "American Journal of 

 Science," printed in January, 183 1, demonstrated his right to 

 a place among advanced investigators in the field of electro- 

 magnetism, and led to his election, in 1832, to the professor- 

 ship of Natural Philosophy in the College of New Jersey, 

 where he remained for fourteen years. Of his life at Prince- 

 ton Professor Asa Gray has written : 



" Here he taught and investigated for fourteen fruitful and 

 happy years ; here he professed the faith that was in him, 

 entering into the communion of the Presbyterian Church, in 

 which he and his ancestors were nurtured ; and here he 

 developed a genius for education. One could count on his 

 being a clear expositor, and his gifts for experimental illus- 

 tration and for devising apparatus had been already shown. 

 But now, as a college professor, the question, how to educate, 

 came before him in a broader way. He appreciated, and he 

 made his associates and pupils appreciate, the excellence of 

 natural philosophy for mental discipline, for training at once 

 both the observing and the reasoning faculties. A science 

 which rises from the observation of the most familiar facts, 

 and the questioning of these by experiment, to the considera- 

 tion of causes, the ascertaining of laws, and to the most re- 

 condite conceptions respecting the constitution of matter and 

 the interplay of forces, offers discipline to all the intellectual 

 powers, and tasks the highest of them. Professor Henry 

 taught not only the elementary facts and general principles 

 from a fresh survey of both, but also the methods of philo- 



