NOTES AND MEMORANDA. 39 



The photograph of the writing was made fii'st, and is the best of a 

 number of trials. I then inserted the Nobert's plate, not even 

 changing the cover correction, as I should have done to secure the 

 best definition, because this would have changed the power. The 

 pictiu'e sent was the result. A comparison of the two pictures will 

 render any remarks on the relative delicacy of Mr. Webb's work and 

 that of Nobert imnecessary. It is evident that the point used by the 

 former is very much coarser than that used by the latter. The 

 pictui-e of the Prayer, mounted dry, was taken on a subsequent occa- 

 sion, and is also the best of a number of trials. It is taken with the 

 same objective as the other pictures, but with a different cover correc- 

 tion, and somewhat greater distance. Both the samples sent me by 

 Mr. Webb are inscribed on such thick covers that they are seen under 

 a disadvantage, and my highest powers cannot be used on them. The 

 writing is, however, comparatively so coarse that it can hardly be 

 considered as a serious test for high powers. Either plate is easily ' 

 read with a good half -inch objective and central light. I am curious 

 to learn how this writing of Mr. Webb's compares with that of 

 Mr. Peters, described by the late Mr. Farrants in his address as 

 President of the Eoyal Microscopical Society. He stated that it was 

 executed at the rate of twenty-two Bibles to the inch. I would 

 greatly like to see such a specimen, and give it a photographic trial. 

 Will you kindly read this note to the Club, and present the photo- 

 graphs ? I send also a full set of my last photographic analysis of 

 Nobert's plate for the Club, and a package for Mr. Webb, which I 

 beg you to hand him." 



A Spherical Diaphragm is thus described in the 'American 

 Naturalist ' by Mr. F. B. Kimbal. He says : — " Wishing to use tubular 

 diaphragms with my microscope, and knowing how clumsy the 

 ordinary ones are, I set to work, and endeavoured to devise a 

 substitute. I made a globe 1^ inch in diameter, and di-illed holes 

 through it of the proper grade of sizes, and adjusted it so that 

 by a spring stop the holes will correspond to the axis of the micro- 

 scope when the ball is revolved on its axis by a milled head at the 

 right of the stage. The fittings are so arranged that the dia- 

 phragm may approach or recede from the stage so as to touch the 

 slide or be far from it. The globe may be made hollow and the 

 lower part cut off if the tubular wells are not desired. I think this 

 form of diaphragm offers many advantages over the ordinary piece of 

 apparatus." 



A New Microscopical Society has been formed at Louisville, Ken- 

 tucky, U.S.A., which meets the first and third Thursdays of each month. 

 • The follo\ving are the names of the ofiicers for the ensuing year: — 

 President, J. Lawrence Smith; Vice-Presidents, Noble Butler, Chas. 

 F. Carpenter ; Treasurer, C. T. F. Allen ; Cor. Secretary, E. S. Crosier ; 

 Secretary, John Williamson ; Executive Committee, Thos. E. Jenkins, 

 James Knapp, W. T. Beach, E. E. Palmer, R. C. Gvvathmey. 



