JOSEPH HENRY 123 



ment and study that he accepted an invitation to go on a survey- 

 ing expedition to the western part of the state. As a result of 

 this expedition he published a topographical sketch of New 

 York which appeared in the Transactions of the Albany In- 

 stitute. It comprised a sketch of the physical geography of the 

 state with especial reference to the newly inaugurated canal 

 system. fL**^^s*JUt- O> f***^*Mj/ y 



In this wnrfc Jia rgn^^itjoT^w^ rgmpfc f f ?y JfiStTgSiL anc * ne 



returned home with a health and vigor which never failed him 

 during the remainder of his long and arduous life. Soon after 

 his return he was elected Professor of Mathematics in the Albany 

 Academy. Here a new field was opened to him. It is one of 

 the most curious features in the intellectual history of our country 

 that, after producing such a man as Franklin, it found no succes- 

 sor to him in the field of science for half a century after his 

 scientific work was done. There had been without doubt plenty 

 of professors of eminent attainments who amused themselves 

 and instructed their pupils and the public by physical experi- 

 ments. But in the department of electricity, that in which 

 Franklin took so prominent a position, it may be doubted 

 whether they enunciated a single generalization which will enter 

 into the history of the sciences. This interregnum closes with 

 the researches now commenced by Professor Henry^ 



That these researches received the attention that they did and 

 led to the author holding so high a place in the estimation of his 

 fellow-men must be regarded as very creditable to the people of 

 Albany at that time, at a period of our history when the question 

 of supposed usefulness was apt to dominate all others. It was 

 then seventy years since Franklin had drawn electricity from the 

 clouds, and fifty years since Volta and Galvani had shown how an 

 electric current could be produced by dropping metals into acid; 

 and what effect such a current had on the legs of a frog. And 

 yet, during these two generations, no one had any idea that these 

 discoveries could ever be put to any practical use, except so far 

 as the destructive agency of lightning could be annihilated by 

 steel-pointed conductors. Under such conditions Henry might 



