528 PROCEEDINGS OF THE SOCIETY. 



microscopy. If, further, it wcro desired to apply photography to tho 

 Microscope, the microscopist should either master tho technicalities of 

 photography, or call in trained assistance in that department. He 

 thought it was hardly treating the Society fairly to suhmit to their notico 

 photomicrographs which showed neither skilful manipulation with tho 

 Microscope nor passably good photography. Several of the photomicro- 

 graphs recently received from America seemed to him extremely defec- 

 tive ; they evidenced utter want of training in the management of the 

 Microscope, selection of the object, &c, while as to tho photography, it 

 was simply beneath criticism ; the negatives were all over-exposed or 

 under-exposed, over-developed or under-developed. He must, however, 

 admit that the prints were well burnished ; that was their one redeeming 

 point. 



Mr. T. C. White said he could quite endorse Mr. Mayall's opinion 

 as to the necessity for strictly centering the condenser ; if this was not 

 done, they would get half the field in shade and the other half in light. 

 It must be properly centered and then moved back until they got an 

 equal illumination all over, and this was equally necessary, whether 

 they worked with high powers or low. It was also quite a matter of 

 common experience that most of the photographs they saw were like 

 those which had been handed round, some being very much under- 

 exposed, and some over-exposed. 



Mr. J. D. Hardy said there were two considerations of importance in 

 the suggestions made for improving a photograph by taking it first with 

 a low power and afterwards enlarging it. In photographing a Floscule 

 under a high power he should want more time and more light, but by 

 using a low power first he took much less time over the process, and 

 thus got a perfect image ; whereas if a longer time had been required, 

 the Floscule might have moved meanwhile, and so spoilt the result. Also 

 the effects of vibration in taking a large image would be reduced so 

 much by taking a low-power image first, that he thought a great advan- 

 tage would be gained on that account. 



Mr. J. Mayall, jun., said that, as regarded the subject of the original 

 communication, he thought there was both truth and untruth in the 

 recommendation. Where a power of x 100 was enough to show the 

 structure of the object, then he would say do as the authors recommended ; 

 but if it needed a power of X 500 to reveal the structure, then it was 

 of no use whatever to photograph with x 100 and afterwards enlarge 

 to x 500. 



Mr. Crisp called attention to Galland-Mason's " Microphotoscope," 

 and read extracts from the inventor's patent specification. {Ante, p. 281.) 



Mr. Kitton's communication was read describing a new species of 

 Biddulphia (B. echinata) from Fiji, specimens of which were shown 

 under Microscopes in the room. (Supra, p. 466.) 



Dr. It. H. Ward's report on his examination of Fasoldt's plates of 

 ruled lines was read, in which he showed that the maker himself was 

 in reality unable to see more lines to the inch than the Abbe theory 

 allowed should be visible. (Ante, p. 298.) 



