716 PROCEEDINGS OF THE SOCIETY. 



mounted on glazed cards, which may, with imperfect washing, have 

 now tended to lessen the intensity of the print." 



Mr. Crisp referred to a letter from a friendly critic as to the 

 extent to which the various matters brought before the Society had to 

 be condensed in order to include them within the compass of the 

 meetings. Two alternatives were open, either to deal with two or 

 three subjects at length, or to refer with more brevity to a greater 

 number. Hitherto the Fellows had desired the latter course, but there 

 V70uld certainly be no objection, on that side of the table at any rate, 

 to adopt the first alternative if the Fellows generally desired it. 



Mr. Beck, speaking not only for himself but as he believed for 

 the Fellows generally, expressed his strong preference for the mode in 

 which the meetings were at present conducted. If there was anything 

 new or interesting they were sure that it would be brought before 

 them, and there could be no dispute as to the fact that for interest 

 and variety of matter the Society was second to none in regard to its 

 meetings. 



The following Notes, &c., were taken as read :— 

 The invention of the Binocular Microscope (see p. 693). 

 Conditions of Aplanatism for wide-angled pencils. 

 Diffraction as regards opaque objects and isolated elements. 

 Aperture and Professor Clausius' theory. 



The action of immersion condensers in the case of apertures ex- 

 ceeding 1 • 00 N. A. 



The following Instruments, Objects, &e., were exhibited:— 



Mr. Crisp — (1) Verick's Mineralogical Microscope, with mechanical 

 stage and objective " extractor " (see p. 662). (2) Verick's Dissecting 

 Microscope (see p. 659). (3) Gundlach's Periscopic Eye-piece (see 

 p. 659). (4) Woodward's Apertometer (ii. (1879) p. 781). (5) Pen- 

 nock's Eye-shade for the Monocular (see p. 518). 



Prof. P. Martin Duncan — Sponge Spicules in illustration of his 

 paper. 



Mr. E. M. Holmes — Specimens in illustration of his paper on a new 

 British Alga. 



Mr. Ingpen — Zeiss's Camera Lucida. 



Dr. Maddox — Two Photographs of Pleurosigma angulatum. 



Mr. T. Powell — Oil-immersion objective of 1 • 47 N. A. 



Prof. P. F. Reinsch — New vegetable structures from Coal. 



Dr. B. Wills Eichardson — The slides mentioned above. 



New Fellows. — The following were elected Ordinary Fellows : — 

 Messrs. A. S. Bishopp, J. Barrow, G. F. Dowdeswell, R. L. Huzzey, 

 M. Johnson, and R. H. Ward. 



Walter W. Reeves, 



A ssist. -Secretary. 



