140 
PROCEEDINGS OF THE SOCIETY. 
Mr. E. B. Stringer’s paper 4 On a new Form of Photomicrographic 
Camera and Condensing System ’ was, in the absence of the author, read 
by Mr. F. W. Watson Baker, the apparatus described being exhibited 
in the room with oxy hydrogen lamp complete. 
Mr. T. Comber said he had only seen the arrangement since he 
came into the room. As his work was done by sunlight, artificial illu- 
mination was a subject which he did not know much about. He had 
consequently very little to say, except that the source of illumination 
appeared to him to be a very valuable arrangement for those persons 
who were obliged to do their work by artificial light. The method of 
obtaining a parallel beam also seemed to be a most excellent one. 
Looking at the image projected on the card, however, it did not seem to 
be quite flat, so that the picture was sharp in the centre, but fell off 
towards the margin of the field. Possibly this might be in some measure 
due to the objective, but in any case the apparatus seemed to possess 
great potential powers. 
Mr. F. W. Watson Baker said that the want of flatness of field was 
obviously due to the objective, the one used for the purpose of exhibition 
being a 1/6 in. oil-immersion having a numerical aperture of 1*30. 
The President said that he had had the advantage of seeing the ap- 
paratus at work at Messrs. Watson’s. It was on an entirely different 
plan to his own apparatus, because he never used any optical arrange- 
ment between the light and the substage condenser,, except a heat inter- 
ceptor and screens. There was, moreover, no fixed position for his 
Microscope, as he preferred to centre his plate to the axis of the Micro- 
scope rather than the Microscope to the plate. It was, however, a case 
of tot homines tot sententise, especially with photomicrographers. The 
reduction in the pressure of the gas was most important, a low pressure 
of gas being necessary to obtain a small and steady light. He had not 
used zirconium, but from what he had seen that evening, he thought it 
a most excellent form of artificial light. The adjustability of all the 
parts was an excellent idea, because they could be quickly and accurately 
centered. With regard to the apparent divergence of the beam issuing 
from the water trough, it was due to the magnification of the system, 
and not to the want of parallelism of the pencils, as had been suggested ; 
a Galilean opera or field glass would produce the same effect. He 
■would conclude by congratulating Mr. Stringer on his success. 
The thanks of the Society were unanimously voted to Mr. Stringer 
for his paper, and to Mr. Baker for reading it on that occasion. 
Prof. Bell said that a selection of slides of sections of Echinus spines 
from the Tucker Collection in the Society’s Cabinet, were exhibited 
under a number of Microscopes in the room that evening. 
Prof. Bell having intimated that the next meeting of the Society 
would be its Annual Meeting, read a list of nominations for Officers and 
Council to be then submitted for election. He also said that the Council 
had appointed Mr. Dadswell to act on their behalf as Auditor of the 
Treasurer’s accounts for the past year, and asked the Fellows present 
to elect another Auditor to act for them. 
