president's address. 33 



intention was always a high one, that of making meeting easier, 

 and, therefore, mutual work readier, this is by no means the 

 inevitable consequence. There is frequently ultimate in- 

 efficiency, and, at times, a total dwindling away. 



There can be small doubt, in my judgment, that all such 

 societies, especially in a city like this, if formed at all (and 

 there may be good reasons for forming them), should not be 

 considered as supplanting a central society such as ours. 



Even with men of science and microscopists there is a sense 

 in which there is " power in numbers," but beyond this there is 

 influence in persons. Men, known and distinguished, whether 

 as professionals or amateurs, always exert upon younger and 

 aspirant minds an influence, while the esprit de coeur is not 

 without its effect ; and the larger communion and larger 

 opportunity for the comparison of work is always powerful. 

 Without doubt, it would promote the largest and best 

 interests of amateur microscopy, in both London and the great 

 provincial cities, if the sectional club in the suburbs, con- 

 ducted with great economy, was normally considered an 

 appendix to, and not a supplanter of, the original and central 

 society. 



In the position I occupy to-night, it is, of course, easy to go 

 hastily over the work which has been done by the Club during 

 the year. But I doubt if this is complimentary, either to the 

 work done or to you, who have already received and discussed 

 it ; it carries with it, too, the defect of all cursory glances. 

 But I am constrained to refer to one subject to w^hicli our 

 attention has been called during the year. 



I discussed last year the merits of the remarkable new 

 object-glass produced by the firm of Zeiss, having the great 

 numerical aperture of 1-60 and a magnifying power indicated 

 by 2'5 m.m. It was shown that while this glass had remark- 

 able properties, and formed a beautiful image, yet it w^as in- 

 efficient : 



(1.) Because it was not provided with even an achromatic 

 condenser of equivalent angle, but was worked of necessity, if 

 all its N.A. was utilized, with a condenser of dense flint, with 

 both spherical and chromatic aberration absolutely uncorrected. 



(2.) Since its N.A. was so great, it could only be illumi- 

 nated and its image formed through homogeneous media, com- 



JouRN. Q. M. C, Series II., No. 31 3 



