WILLIAM PRESCOTT DEXTER. 363 



genuity of metallic construction was especially necessary ; for this, 

 as has been said, was the province in which Mr. George B. Clark's 

 abilities were most marked. When the gearing required in the appa- 

 ratus for determining the velocity of light, constructed for Professor 

 Newcomb, proved to be soon worn out by the rapidity of revolution 

 required, Mr. Clark succeeded in applying the necessary remedy by 

 introducing raw hide into a certain part of the apparatus, instead 

 of metal. Among the instruments made for Harvard College Ob- 

 servatory and other institutions of Cambridge and Boston, in the 

 construction of which his skill and zeal were peculiarly advantageous, 

 may be mentioned several large spectroscopes, photometers, and pho- 

 tographic instruments. 



The singularly genial and kindly temperament which Mr. Clark in- 

 herited from his beloved father insured him cordial regard, and even 

 affectionate sympathy, among a wider circle than that of his immediate 

 relatives and associates. His face and manner bore a stamp of refine- 

 ment of feeling which would not have been expected in a man whose 

 education and whose occupations were of so exclusively practical a 

 character. His incessant devotion to his business left him no leisure 

 for those pursuits which are traditionally regarded as tending to pro- 

 mote gentleness as well as gentility ; but nature had supplied him in 

 this respect with more merit than most men can acquire by training. 



He was married in 1857 to Miss J. M. Mosely, who survives him ; 

 but he left no children. Although the failure of his health had for 

 several years been evident, his death by apoplexy on December 20, 

 1891, found him still busy with his work. His memory will be 

 cherished by all who knew him, and the instruments which he 

 planned will long testify to his skill by the scientific results which 

 they furnish. 



WILLIAM PRESCOTT DEXTER. 



William Prescott Dexter was the son of Franklin Dexter and 

 of Elizabeth, daughter of Judge William Prescott. He came of dis- 

 tinguished ancestry. His great-grandfather on the mother's side com- 

 manded the American troops at Bunker Hill. The historian William 

 Hickling Prescott was his uncle. His grandfather, Samuel Dexter, 

 was an eminent statesman. Both his grandfathers were members of 

 this Academy, and they held high rank as lawyers, as did his father 

 also. All of them were prominent citizens. So too was his distant 

 kinsman, Aaron Dexter, M.D., likewise a member of this Academv. 



