COMMEMORATIVE ADDRESS 5 



but were able to show that the results were in tolerably close agreement 

 with computed values. The repetition of the experiment by Himstedt 

 in the same year resulted in the same way, but in 1897 the genuineness 

 of the phenomenon was again called in question by a series of experi- 

 ments made at the suggestion of Lippmann, who had proposed a study 

 of the reciprocal of the Rowland effect, according to which variations 

 of a magnetic field should produce a movement of an electrostatically 

 charged body. This investigation, carried out by Cremieu, gave an 

 absolutely negative result, and because the method was entirely differ- 

 ent from that employed by Eowland and, therefore, unlikely to be 

 subject to the same systematic errors, it naturally had much weight 

 with those who doubted his original conclusions. Realizing the neces- 

 sity for additional evidence in corroboration of his views, in the Fall 

 of the year 1900, the problem was again attacked in his own laboratory 

 and he had the satisfaction, only a short time before his death, of 

 seeing a complete confirmation of the results he had announced a 

 quarter of a century earlier, concerning which, however, there had 

 never been the slightest doubt in his own mind. It is a further satis- 

 faction to his friends to know that a very recent investigation at the 

 Jefferson Physical Laboratory of Harvard University, in which Row- 

 land's methods were modified so as to meet effectively the objections 

 made by his critics, has resulted in a complete verification of his 

 conclusions. 



On his return from Europe, in 1876, his time was much occupied 

 with the beginning of the active duties of his professorship, and 

 especially in putting in order the equipment of the laboratory over 

 which he was to preside, much of which he had ordered while in Europe. 

 In its arrangement great, many of his friends thought undue, promi- 

 nence was given to the workshop, its machinery, tools, and especially 

 the men who were to be employed in it. He planned wisely, however, 

 for he meant to see to it that much, perhaps most, of the work under 

 his direction should be in the nature of original investigation, for the 

 successful execution of which a well-manned and equipped workshop is 

 worth more than a storehouse of apparatus already designed and used 

 by others. 



He shortly found leisure, however, to plan an elaborate research upon 

 the Mechanical Equivalent of Heat, and to design and supervise the 

 construction of the necessary apparatus for a determination of the 

 numerical value of this most important physical constant, which he 

 determined should be exhaustive in character and, for some time to 



