PROCEEDINGS OF THE SOCIETY. 
599 
MEETING 
Held on the 17th of November, 1897, at 20 Hanover Square, W. 
E. M. Nelson, Esq., President, in the Chair. 
The Minutes of the special and ordinary meetings of 20th October 
last were read and confirmed, and were signed by the President. 
The Secretary said that the only donation to the Society (exclusive 
of exchanges) which he had to report was volume iv. of Dr. de Toni’s 
1 Sylloge Algarum.’ 
The thanks of the Society were voted to Dr. de Toni for this dona- 
tion. 
The Secretary said that a vacancy having occurred in their list of 
Honorary Fellows, it was proposed to elect Mr. Arthur Belles Lee, of 
Nyon, to fill this vacancy; a nomination paper was accordingly read, 
and ordered to be suspended until the next ordinary meeting. 
Mr. J. W. Measures exhibited and described a new binocular dis- 
secting Microscope, in which a direct image was obtained by means of 
Porro’s prisms, a further peculiarity being that the image in each eye- 
piece was formed by a separate objective, the two objectives being fitted 
together at an angle which, at the focal distance, admitted of the axis of 
each passing through the same point. There was an arrangement by 
which the distance apart of the eye-pieces could be regulated to suit the 
eyes of the observer, and provision was made for both dark and light 
ground illumination. The image seen was ortho-stereoscopic, and hand- 
rests were fixed on either side of the stage, as was usual in the case of 
dissecting Microscopes. The Microscope was made by Zeiss. 
Mr. A. D. Michael inquired up to what power this arrangement was 
available, and whether there was not a loss of light consequent upon the 
use of these prisms. He fancied that the use of an instrument of this 
kind would be confined to dissection with low power, and he feared 
that the loss of light would prove a difficulty if higher powers were at- 
tempted. For large objects and under low magnifying powers it would 
probably be a very handy instrument, but for very delicate dissections 
under high powers, he doubted if it would be successful. 
Mr. Measures said this Microscope was only intended for use in dis- 
secting with low powers. He did not know how far it would be possible 
to work it with objectives of higher pow'er than those on the Micro- 
scope. 
Mr. Beck asked at what angle the two objectives were inclined 
towards the object. After inspection, he thought the angle was about 
equal to that of the eyes placed about 6 in. apart, and that it would 
consequently give undue stereoscopic effect. 
The President said that some years ago he felt very much interested 
in this kind of thing, and in the course of his experiments he made a 
1897 2 T 
