December 6, 1901.] 



SCIENCE. 



867 



mony with his bold spirit, his extraordi- 

 nary power of analysis and his quick rec- 

 ognition of the relation of things. By the 

 aid of apparatus entirely of his own con- 

 struction and by methods of his own de- 

 vising, he had made an investigation, both 

 theoretical and experimental, of the mag- 

 netic permeability and the maximum mag- 

 netization of iron, steel and nickel, a sub- 

 ject in which he had been interested in his 

 boyhood. 



On June 9, 1873, in a letter to his sis- 

 ter, he says : *' I have just sent off the re- 

 sults of my experiments to the publisher 

 and expect considerable from it ; not, how- 

 ever, filthy lucre, but good, substantial 

 reputation." What he did get from it, at 

 first, was only disappointment and discour- 

 agement. It was more than once rejected 

 because it was not understood and finally 

 he ventured to send it to Clerk Maxwell, in 

 England, by whose keen insight and pro- 

 found knowledge of the subject it was in- 

 stantly recognized and appraised at its full 

 value. Regretting that the temporary 

 suspension of meetings made it impossible 

 for him to present the paper at once to the 

 Eoyal Society, Maxwell said he would do 

 the next best thing, which was to send it to 

 the Philosophical Magazine for immediate 

 publication, and in that journal it appeared 

 in August, 1873, Maxwell himself having 

 corrected the proofs to avoid delay. The 

 importance of the paper was promptly rec- 

 ognized by European physicists, and 

 abroad, if not at home, Rowland at once 

 took high rank as in investigator. 



In this research he unquestionably anti- 

 cipated all others in the discovery and an- 

 nouncement of the beautifully simple law 

 of the magnetic circuit, the magnetic ana- 

 logue of Ohm's law, and thus laid the 

 foundation for the accurate measurement 

 and study of magnetic permeability, the im- 

 portance of which, both in theory and in 

 practice during recent years, it is difiicult to 



overestimate. It has always seemed to me 

 that when consideration is given to his age, 

 his training, and the conditions under 

 which his work was done, this early paper 

 gives a better measure of Rowland's genius 

 than almost any performance of his riper 

 years. During the next year or two he 

 continued to work along the same lines in 

 Troy, publishing not many, but occasional, 

 additions to and developments of his first 

 magnetic research. There was also a paper 

 in which he discussed Kohlrausch's deter- . 

 mination of the absolute value of the Sie- 

 mens unit of electrical resistance, foreshad- 

 owing the important part which he was to 

 play in later years in the final establish- 

 ment of standards for electrical measure- 

 ment. 



In 1875, having been appointed to the 

 professorship of physics in Johns Hopkins 

 University, the faculty of which was just 

 then being organized, he visited Europe, 

 spending the better part of a year in the 

 various centers of scientific activity, in- 

 cluding several months at Berlin in the 

 laboratory of the greatest continental 

 physicist of his time, von Helmholtz. 

 While there he made a very important 

 investigation of the magnetic effect of 

 moving electrostatic charges, a question of 

 first rank in theoretical interest and sig- 

 nificance. His manner of planning and ex- 

 ecuting this research made a marked im- 

 pression upon the distinguished director of 

 the laboratory in which it was done and, 

 indeed, upon all who had any relations 

 with Rowland during its progress. He 

 found what von Helmholtz himself had 

 sought for in vain, and when the inves- 

 tigation was finished in a time which 

 seemed incredibly short to his more delib- 

 erate and painstaking associates, the di- 

 rector not only paid it the compliment of 

 an immediate presentation to the Berlin 

 Academy, but voluntarily met all expenses 

 connected with its execution. 



