PROCEEDINGS OF THE SOCIETY. 
MEETING 
Held on the 18th of December, 1895, at 20 Hanover Square, W., 
the President (A. D. Michael, Esq., F.L.S.) in the Chair. 
The Minutes of the Meeting of 20fch November 1895, were read and 
confirmed, and were signed by the President. 
The List of Donations (exclusive of exchanges and reprints) received 
since the last meeting, was submitted, and the thanks of the Society 
were given to the donors. 
From 
Monographs of tlie United States Geological Survey, xxiii.l The United States 
and xxiv. (4to, Washington, 1894) / Geological Survey. 
C. Babbage, Table of Logarithms. (8vo, London, 1872) .. Mr. W. T. Suffolk . 
Dr. W. H. Dallinger read a letter received from Mr. Hammond of 
the Borough Polytechnic, asking for the aid of the Society in procuring 
Microscopes for their conversazioni arranged to take place on December 
27th, 28th, 30th, and 31st. He said that the Society was of course 
unable to exhibit anything, as a Society, but if any of the Fellows were 
able to render any assistance in that way he was sure it would be much 
appreciated. 
Mr. E. M. Nelson exhibited a. Microscope which, though of a pattern 
previously described, differed in one or two points which had been 
recently added. The instrument would no doubt be recognised as one 
of Mr. Swift’s portable Microscopes, but the stage had been enlarged to 
4J in. by 5J in., which gave it an advantage in being able to carry tho 
larger specimens and sections which it was now often required to 
examine. The other point was that the body was fitted with three 
draw-tubes giving a range of length from 4J in. to 12J in., which would 
no doubt be sufficient to suit objectives corrected for every distance 
l'kely to be met with. The additional draw-tubes were no doubt fitted 
at some cost to the steadiness of the instrument, but he thought this 
could be overlooked in the face of the advantage derived from being able 
to adapt the tube-length to the correction of the objective in use. The 
Microscope was also fitted with a differential screw-adjustment, cut with 
French threads so that the motion could be divided into parts of a 
millimetre. The mirror could also be rotated to get rid of tho multiple 
image. 
He also exhibited a new optical rule, made by Stanley, for facili- 
tating simple optical calculations as to the power of lenses. It was 
square in section, one side being marked in inches and tenths, and 
the opposite side in millimetres. On one of the other sides there was a 
