Mar., 1905.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



69 



recently as June last. The address was illustrated by 

 many lantern slides and by sections of fossils from the 

 coal-measures shown on the screen, whilst Professor 

 F. W. Oliver kindly lent a number of specimens, and 

 Mr. Smedly, F.L.S., exhibited some beautiful large scale 

 models. 



The Quekett Microscopica.! Club. 



The 419th ordinary meeting of the Club was held on 

 January 20 at 20, Hanover Square, the President, Dr. 

 E. J. Spitta, V.P.R.A.S., in the chair, The death of 

 Professor Ernst Abbe, who had been an honorary mem- 

 ber of the Club since 1879, was announced, and a motion 

 recording the Club's appreciation of his services to 

 microscopy and sympathising with his family in their 

 loss was unanimously adopted. Mr. C. F. Rousselet, 

 F.R.M.S., then gave a detailed description of his well- 

 known compressor, describing the various features which 

 he had considered essential to the object which he had in 

 view when designing it, viz., the examination of the 

 smallest living rotifers under high power objectives and 

 with critical illumination from modern wide-angled con- 

 densers. The model was completed in 1893, ^""^ had 

 been in use ever since with such success that he had 

 found no openings for alteration or improvement. The 

 various so-called " Improved Rousselet Compressors " 

 which were on the market were, in his opinion, anything 

 but improvements upon the original model, and he 

 strongly disapproved of them. The Hon. Secretary 

 then read a note by Mr. A. E. Merlin, F.R.M.S., 

 " On the cut suctorial tubes of the Drone Fly's proboscis 

 as a suggested test object for medium powers." Mr. 

 Merlin pointed out the difficulties attaching to the use of 

 the Blow Fly proboscis as a test for the ^" or 1" objec- 

 tive, in the hands of a tyro. Formerly the Podura scale 

 was the most satisfactory test for such powers, but it 

 was difficult nowadays to obtain a slide. The Drone 

 Fly's proboscis was in structure similar to the Blow 

 Fly's, but the detail was finer. 



Bausch &rvd Lomb's New Portable 

 Microscope. 



Messrs. A. E. Staley and Co. have sent me for inspec- 

 tion their new " B.B.P." portable microscope. This is a 

 full-size microscope of the Continental type, with large 

 vulcanite stage, sub-stage adjustable by spiral rack and 

 pinion carrying condenser and iris diaphragm, coarse and 

 fine adjustments, draw-tube, &c. The stage is, however, 



mounted on an axis, so that it, with its condenser in 

 place, can be swung into a vertical position, a clamp fix- 

 ing it when in the horizontal position, whilst the base 

 folds together. The microscope, with objectives and eye- 

 pieces, goes into a case measuring iif x 8 x 4^ inches. 

 This is, of course, not one of the most compact micro- 

 scopes, the idea being to retain all the advantages of the 

 full-size microscope and to add portability. The case is, 

 therefore, too heavy for carrying any great distance. The 

 instrument is beautifully finished, as are all microscopes 

 made by the Bausch and Lomb Optical Company ; the 

 objectives are excellent, and the case is exceptionally 

 handsome. The fine adjustment was, however, some- 

 what coarse in movement, whilst in the instrument sent 

 me the condenser did not quite focus. The tube was of 

 the Continental size and length, and the objectives were 

 marked with tube-length, numerical aperture, and power, 

 which I wish one could see on all objectives. There was 

 also an extra diaphragm immediately beneath the stage ; 

 but this is, I always think, an unnecessary luxury. 



The Postal Microscopical Society. 



A perusal of the Annual Report of this Society makes 

 one feel that its limited membership can only be due to 

 the fact that its very existence must be unknown to the 

 vast majority of those amateur microscopists to whom it 

 specially appeals. The Society was founded in 1873 by 

 the late Alfred Allen, of Bath, and its mode of working is 

 briefly as follows : Each member contributes a dozen 

 slides — his own make if possible ; if not, good purchased 

 ones. To these he adds a small notebook and notes on 

 the various slides. The notes may or may not be entirely 

 original, but they are explanatory, and there may even 

 be one or two drawings illustrative of certain points. If 

 the slides are his own mounting, he adds a few notes as 

 to how he mounted them, and he may also ask for infor- 

 mation or help on various matters from other members 

 who will see his slides and notes. The box of slides goes 

 in to the Secretary, who adds four slides from the 

 Society's cabinet, making 16 in all. The members are 

 divided up into " circuits " of seven members each, and 

 the boxes with their notes pass on from member to mem- 

 ber at intervals of six days, each member adding a few 

 notes to the notebook as he passes it on. When the box 

 has made its complete round of all the " circuits " it 

 returns to its owner, who keeps it, the notebook, and the 

 four additional slides, he himself having meanwhile, of 

 course, been the due recipient of all the other boxes in 

 due turn. This is the ideal arrangement, but it is departed 

 from, when members fail to send on their boxes according 

 to the rules, and fail to add notes and comments other 

 than expressions of regret for their remissness. It will 

 be seen that the whole scheme is simple in the extreme, 

 and it gives to every member an opportunity of seeing 

 and studying at leisure a large number of slides on very 

 varied subjects, of interchanging views with brother or 

 sister enthusiasts, and of getting assistance on thorny 

 points. Such a Society will, of course, appeal almost 

 entirely to amateur microscopists ; but to them it should 

 be of real service, and I would suggest that any of my 

 readers who are interested should write to the Hon. 

 Secretary, Miss Florence Phillips, 3, Green Lawn, Rock 

 Ferry, Cheshire, for further particulars. The subscrip- 

 tion is five shillings per annum, with a small entrance 

 fee. 



[Communications and enquiries on Microscopical matters are invited, 

 and should be addressed to F. Shillington Scal:s, "Jersey," St., 

 Barnabas Road, Cambridge.] 



