1884.] 



MICROSCOPICAL JOURNAL. 



11 



I first met Mr. Tolles about the 

 year 1870, and was so impressed with 

 his intelligence, his modesty and gen- 

 tlemanly bearing, that it was always 

 after a pleasure to meet him. He 

 was very ingenious, very skilful with 

 hand and eye, and always willing to 

 aid in designing and arranging de 

 vices for the microscope. Of course 

 he is best known for his skill in mak- 

 ing high-po"wer objectives, but with 

 greater facilities he might have been 

 as famous in other departments of 

 optical work. 



After making the objectives which 

 Dr. Woodward made famous by his 

 photographs (August, 1S72), Mr. 

 Tolles made no decided improvement 

 for some time. In fact, the water- 

 immersion system had about reached 

 its limits. Before this, however, he 

 had constructed objectives which he 

 claimed had a balsam angle, but this 

 claim ^vas not generally recognized 

 for some years. After the use of im- 

 mersion fluids of a higher refractive 

 index than water became known, Mr. 

 Tolles made a decided advance in the 

 quality of his objectives. I have ex- 

 amined many of his homogeneous 

 immersion objectives, and compared 

 them with my Zeiss ts (a duplicate 

 of the one described by Dr. Wood- 

 ward yournal R. M. S.^ p. 663), 

 and w^hile all could well bear the com- 

 parison, most were fully equal to the 

 Zeiss. 



But your space will not permit an 

 extended review of Mr. Tolles's work. 

 I w^ill, therefore, refer to an incident 

 which had an important effect in facil- 

 itating the testing of his balsam angle 

 objectives. In the spring of 1875 he 

 passed an evening with me, not know- 

 ing w^hat was to be shown him. Be- 

 fore he arrived I arranged my micro- 

 scope horizontally, having on the stage 

 a Probe Platte, illuminated with 

 Wenham's reflex illuminator. The 

 objective was a water-immersion tV, 

 made by himself. The light (a kero- 

 sene lamp) was placed axially and the 

 resolution of Amphipleura -was ac- 

 complished from end to end of the frus- 



tule. I threw a cloth over the objec- 

 tive and illuminating apparatus. On 

 looking through the microscope he 

 savv^ at once the resolution and was 

 greatly astonished on learning that 

 the amphipleura was on a Probe 

 Platte and in balsam. He had never 

 seen a resolution of a balsam-mounted 

 amphipleura by lamp-light. (I be- 

 lieve it had never been seen until a 

 short time before when I first ob- 

 served the capabilities of the reflex 

 illuminator.) After his first aston- 

 ishment he became very grave and 

 silent. He afterwards told me that 

 he supposed I had obtained some 

 wonderful objective surpassing any- 

 thing he had seen, and the thought 

 that an objective had been made, un- 

 known to him, and superior to any of 

 his own, was very disappointing. But 

 notwithstanding this feeling, which 

 must have been very depressing to 

 his sensitive nature, he asked no ques- 

 tion, but waited patiently until this 

 superior objective should be uncov- 

 ered. It did not once occur to him 

 that the secret lay in the illumination, 

 and when the cloth was removed and 

 he saw that he had been looking 

 through a Tij of his own, the change 

 that took place in his face was remark- 

 able ; his pleasure and satisfaction were 

 very great, and he again became cheer- 

 ful and chatty. He immediately ap- 

 preciated the operation of the reflex 

 illuminator, and began the next day 

 to make copies with different angles 

 for his own use. This gave him pos- 

 itive tests for his balsam angle ob- 

 jectives, such as he had not before 

 possessed, and saved much time in 

 constructing objectives. 



Mr. Tolles's reputation in telescopic 

 work was not so extensive as in mi- 

 croscopy, but it deserves mention. 

 His introduction of short focus object 

 glasses for telescopes was a great im- 

 provement: He made these glasses 

 from ^-inch to 7 inches in diameter, 

 and it is unfortunate that he did not 

 have an opportunity to construct some 

 larger lenses. The 2|-inch glass was 

 a great favorite ; its definition was 



