PROCEEDINGS OF THE SOCIETY. 1063 



however, this system was open to some objection, because the person 

 using it would be apt to strain the mechanism if he inadvertently tried 

 to move the coarse-adjustment when it was clamped to the fine-adjust- 

 ment. The Microscope before them was very elegantly made, and he 

 thought that Mr. Griffith was much to be congratulated upon its 

 appearance (supra, p. 1022). 



Mr, Crisp read to the meeting Mr. Griffith's description of the fine- 

 adjustment, and showed how the base of the stand being unscrewed from 

 the pillar and inverted upon a pin fixed in the case, formed an effective 

 turntable. 



The President thought the contrivance was very ingenious. 



Mr. Crisp said they had had a great many criticisms in that room as 

 to what constituted ingenuity in this respect, and there were some of 

 the objectors who would consider it open to doubt whether a Microscope 

 was not better if it could not be used as a turntable. 



Mr. Crisp exhibited Cutter's Cam Microscope, with a tilting stage 

 to act as a fine-adjustment, the tilting being effected by eccentric cams 

 turned by a lever. Also, Fasoldt's " Patent " Microscope, by the use of 

 which Mr. Fasoldt claimed that his test-plates could be resolved. It 

 had an arrangement which prevented the body-tube rnnning down on the 

 object, an adapter for rapidly changing objectives, and an elaborated 

 form of Beck's vertical illuminator. 



Mr. Ingpen inquired if anything was said as to any peculiarity in 

 the objectives ? 



Mr. Crisp said the objectives were not mentioned ; the result was 

 said to be due to the method of illumination, which was the vertical 

 illuminator. 



Mr. Crisp exhibited and described Zeiss's " micron " eye-piece micro- 

 meter, which obviates the necessity for constructing tables giving the 

 value of an interval for each eye-piece and objective (ante, p. 797). 



Mr. Rowland's reversible compressorium was exhibited and described 

 by Mr. Crisp (ante, p. 803). 



The President said this was practically the same as one which was 

 made for him by Mr. Swift. This he gave up as useless, because, in conse- 

 quence of the two surfaces of glass not being absolutely parallel to one 

 another, the water was all carried off to one side. Unless the apparatus 

 was made with a perfectly parallel motion it would be entirely useless. 



Mr. C. Beck also remarked on its resemblance to Wenham's compres- 

 sorium. 



Mr. Crisp exhibited a form of safety stage (sent from America), 

 which was fitted with two screws and nuts, by which the tension of the 

 springs could be regulated as desired. 



Mr. T. F. Smith exhibited some photomicrographs of portions of 

 valves of Pleurosigma formosum, in illustration of what he imagined, from 

 recent observations with high powers, to be the real structure. He had, 

 he considered, discovered at least three layers, and thought there were 

 possibly more. He had found the examination to be a matter of some 



