PEOCEEDINGS OF THE SOCIETY. <)01 



not required. By putting the lens on the telecentric disc, very good 

 results were obtained. 



The Chairman (Mr. Joseph E. Barnard) said be was sure Mr. 

 Cheshire's paper had been extremely interesting, and was indeed such 

 a model of lucidity as might be expected from the author. The method 

 described was a simple one, and what was of most importance seemed to 

 be easily applicable to the Microscope. The ascertaining of the exact 

 focal length of an objective had always been a subject for discussion, 

 for which there seemed to be no sort of finality. Mr. Cheshire's 

 arrangements were simple as well as novel, and all the more meritorious 

 for that reason. The use of a telecentric disc instead of a central spot 

 was one of the most important points in the whole process, and insti- 

 tuted an advance in focometric methods. Further, there was no 

 subsidiary optical system introduced to complicate or lessen the accuracy 

 of the results. There was one little point mentioned by Mr. Cheshire, 

 but which was really outside the range of the subject, and that was the 

 employment of sodium light as a source of monochromatic light. He 

 thought a very much better source was obtained by using the green 

 lines in the spectrum of the mercury arc, as this approached as nearly 

 as possible to the monochromatic light. He wished to express the 

 indebtedness of himself and the Society to Mr. Cheshire for his inter- 

 esting paper, and he was sure that all present would show their appre- 

 ciation of what they had heard. 



In reply to Mr. Barnard's criticism in regard to sodium light being 

 employed as a source of monochromatic light, Mr. Cheshire nodded 

 assent. 



Dr. Shilling-ton Scales gave notice that the next General Meeting- 

 would be asked to suspend By-law 36 so far as related to the President, 

 for twelve months. According to By-law 37, the duty of the present 

 Council was to make up a list of the proposed Council for the ensuing 

 year. Four Ordinary Members would retire, and, according to the rules 

 and by-laws of the Society, nominations for the Council were made in 

 November by the Council, and voted for at the Annual Meeting in 

 January. It had been suggested, however, that Fellows would appreciate 

 more opportunities of nominating Fellows of their own choice to the 

 Council than was provided hitherto, and so it had been arranged that 

 the four vacancies should not have definite nominations made for them 

 by the Council now, but that the Fellows of the Society should be asked 

 themselves to suggest names between now and the next meeting, failing 

 which the Council would proceed in the usual way. If any Fellows 

 present, therefore, wished to take advantage of this proposal, it would 

 greatly facilitate the work of the Council if they would send in their 

 suggestions before the next Council Meeting. 



The Chairman announced that the next Ordinary Meeting would 1 >e 

 held on December 16, when he (Mr. Barnard) would make a com- 

 munication on the subject of X-rays in relation to the Microscope. 



