General Discussion. 



The Chairman invited discussion on the group of 

 papers just presented, and he called on Mr. Barnard to 

 make an announcement. 



Mr. J. E. Barnard : The point that I wish to raise will only take 

 a few moments. It is this, that Messrs. Swift, I understand, 

 have quite recently manufactured a series of apochromatic objectives. 

 There is no particular innovation in that, because they have made 

 them for years, but I believe that they admit that in some small 

 particulars they come short of the German standard. They are so 

 conscious of the superiority of these new objectives, however, that 

 they are anxious that a Committee should decide as to whether these 

 new objectives are the equals, and we sincerely hope we may say the 

 superiors, of those of German manufacture. For this purpose, there- 

 fore, they have suggested, and after consulting with Sir Robert 

 Hadfield we have agreed, that a Committee should be asked to adju- 

 dicate upon them, and therefore Sir Robert Hadfield, as President 

 of the Faraday Society, the Presidents for the time being of the 

 Royal Microscopical Society, the Optical Society, and the Photo- 

 micrographic Society, and perhaps such an eminent authority in the 

 application of objectives to metallography as Sir George Beilby and 

 one or two others, are to be asked to go into the question of the 

 actual value of these objectives, I feel quite sure that that is a 

 proposition that will appeal to the meeting for the part it will 

 play, apart from any other question, in perpetuating the work of 

 this Symposium. Therefore, even if the results arrived at are not 

 all we hope, this Committee and its conclusions will form a very 

 valuable connecting link between this Symposium and any succeeding 

 work. I therefore have pleasure in moving that this Committee be^ 

 authorised to proceed with this question. 



Mr. P. Watson Baker (Messrs. W. Watson and Sons): May I 



enquire whether apochromatic objectives of other English firms can- 

 also be included ? We have made apochromatic objectives for some- 

 years, and are quite willing to submit them. 



Mr. Barnard: T should say there is no question about that. The- 

 reason T brought this up was that Messrs. Swift are the only ones 

 who submitted objectives under the conditions set out, but if any 

 other firm is in the position to submit some, the Committee will be 

 only too anxious to consider them. 



Dr. R. Mullineux Walmsley : I am most interested in this ques- 

 tion from the educational side. One of the main questions before 

 the Symposium is the production of microscopes in large quantities, 

 and I venture to suggest that, as ^\v. Watson Baker says at the 

 end of his paper, the colleges concerned must give him the necessary 



