10 



THE AMEEICAN MONTHLY 



[January, 



apparatus, which we hope Mr. Bul- 

 loch will soon do. 



The stand is also provided with 

 Mr. Bulloch's new detaching nose- 

 piece, which has already been men- 

 tioned in these columns. 



Robert B. Tolles. 



The death of Mr. Robert B. Tolles 

 was briefly announced in the Decem- 

 ber number. The Boston Herald of 

 Nov. 20th contained the following 

 brief summary of Mr. Tolles' busi- 

 ness career : — 



"Mr. Robert B. Tolles, of the Bos- 

 ton optical works, who died at the 

 Massachusetts General Hospital on 

 the 17th instant, had a world-wide 

 reputation as a maker of microscopes, 

 and particularly as a maker of micro- 

 scope objectives, such as are required 

 by and used in the highest class of 

 scientific work. He also contributed 

 as much, if not more than any other 

 optician, toward developing that in- 

 strument and bringing it to its pres- 

 ent high state of perfection. 



"Mr. Tolles was born in Connec- 

 ticut 62 years ago, but at an early age 

 went to New-York, where, while yet 

 a young man, he entered the employ 

 of the firm since widely known as 

 Spencer & Son, optical instrument 

 makers. With the senior member of 

 that firm, Mr. Charles A. Spencer, 

 then at Canastota, he learned the 

 business of grinding lenses and the 

 mechanical construction of micro- 

 scopes and telescopes. After being 

 with Mr. Spencer a number of years, 

 he set up for himself in the same line 

 of business in the same town. He 

 remained there until 1866, when he 

 came to Boston, and, in connection 

 with Mr. Charles Stodder, founded 

 the Boston optical works, w^hich bus- 

 iness connection continued until his 

 death ; and it was here that most of 

 his reputation as a maker of first-class 

 objectives for the microscope was 

 achieved. He was among the first 

 to produce what are known as wide- 

 angle objectives, and to demonstrate 



their superiority in showing the finer 

 details of the structure of objects. 

 Although not the discoverer of im- 

 mersion objectives, he at once recog- 

 nized their great value, and was 

 among the first to manufacture them. 

 Mr. Tolles was the inventor of many 

 valuable accessories, both of the mi- 

 croscope and telescope, but, undoubt- 

 edly, his greatest achievement in this 

 direction vs^as his demonstration of 

 the practicability of the homogeneous 

 immersion objective and its superior- 

 ity over other lenses. This he dem- 

 onstrated in i87i,but owing to the 

 fact that at that time Canada balsam 

 was the only fluid known to possess 

 the same refractive index as crown 

 glass, his discovery remained useless 

 until 18775 when Prof. Abbe discov- 

 ered a fluid which w^as practical for 

 such a purpose. Since then a large 

 number of such objectives have been 

 made and numerous discoveries made 

 by their use, which would have been 

 impossible with the old water-immer- 

 sion lenses. 



" Mi\ Tolles was a very quiet, un- 

 assuming gentleman, who devoted 

 his whole life to his work. He had 

 not been in health for a long period 

 of time, having been a sufterer from a 

 chronic lung disease which most per- 

 sons would have succumbed to years 

 before. In his death the scientific 

 world has sustained a great loss." 



The following letter from a well- 

 known microscopist of Boston will 

 doubtless be more highly valued by 

 our readers than v\^ould a more elab- 

 orate and formal accovint of the life 

 and services of Mr. Tolles, for, com- 

 ing as it does from one who knew 

 him intimately, and embodying such 

 personal recollections as can only 

 come from long association, they re- 

 veal more of his characteristics than 

 could the more high-sounding praises 

 of a stranger : — 



It is with pleasure that I comply 

 with your request to write a few 

 words in memory of Mr. R. B. Tol- 

 les, whose death is a great loss to all 

 microscopists. 



