140 
PROCEEDINGS OF THE SOCIETY. 
any of the views Dr. Nias held concerning the Continental Microscope, 
but merely to point out some inaccuracies upon questions of fact. On 
page 596 it is stated that “the Continental stand has maintained its 
form without substantial alteration for nearly fifty years.” 
Mr. Nelson said that from his own knowledge he could not go back 
as far as fifty years, but during the past twenty-five he had personally 
witnessed the ceaseless changes the Continental Microscope had under- 
gone. Those changes throughout had been in a direction away from 
the Oberhaeuser type, and towards the English model. Even while 
Dr. Nias was reading his paper Leitz was adapting a claw foot and 
horseshoe stage to his Microscope. It must be pointed out that the 
typical Continental Microscope had not followed the Oberhaeuser, for the 
Oberhaeuser had a large stage (4 in. in diameter) whereas the typical 
Continental Microscope had an absurdly small one. The reason for this is 
apparent. A large stage was possible with the Oberhaeuser model, because 
it had a foot as large as, if not larger than, the stage ; but when the narrow 
horseshoe foot was introduced it was necessary to materially lessen the 
diameter of the stage, otherwise a slight pressure on one side of the 
stage would have careened the instrument. It was difficult now to find 
a typical Continental Microscope, but No. V fc in Zeiss’s 1885 catalogue 
might be taken as an example. This Microscope, which was not incli- 
nable, had a horseshoe foot, a sliding tube coarse-, and direct acting screw 
fine-adjustment, its height was 12*2 in., the size of the stage 3 f 2 x 
3*4 in., and price 4Z. 15s. without lenses. This Microscope, which 
was remarkable for the large size of its stage when compared with 
others of its kind (a shade larger than Zeiss No. II.), did not quite con- 
form to type inasmuch as it lacked the peculiar rotation of the limb and 
stage. If, however, one of that kind were selected a still smaller stage 
would be found, viz. one a trifle less than 2^ x 2| in. (Zeiss No. VI. 
1885 catalogue; the microscope is however shorter, viz. 10*6 in.) 
This kind of rotation was disappearing from Continental Microscopes, 
for Zeiss’ 1885 catalogue, out of fourteen varieties of Microscopes, had 
four fitted with it, while his 1889 catalogue had only a single example 
out of twelve varieties. Concurrently with the disuse of this limb and 
stage rotation we found an increasing adaptation of the English method 
of rotation, for in the 1889 catalogue we had the No. II. stand fitted on 
the English plan, instead of on the Oberhaeuser, as in 1885. 
Secondly, Dr. Nias has credited Strauss-Durckheim with priority of 
invention with regard to three points in the construction of the Micro- 
scope, the date of such inventions being given, viz. 1830-5. They are 
as follows : — 
(1) Rotating stage. 
(2) Provision for changing from compound Microscope to simple. 
(3) Erecting Microscope. 
Mr. Nelson said he would not attempt to give the names of the first 
inventors of these several features of microscopical construction, his 
purpose would be served if he quoted an instance predating Strauss- 
Durckheim, viz. ante 1830-5. 
(1) A rotating stage (with rack and pinion movement !) was made by 
Benjamin Martin, 1782. 
(2) During the latter half of the last century many Microscopes had 
