Improvements in the vial microscope / [Cornelius Varley].

  • Varley, Cornelius, 1781-1873
Date:
[1834]
Catalogue details

Licence: Public Domain Mark

Credit: Improvements in the vial microscope / [Cornelius Varley]. Source: Wellcome Collection.

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    into the under returning current, and come back with it. I then placed that side uppermost, and saw them sink again into their former current, and again go on with it. By this means I could confine them to any part of the stem as long as I pleased, and keep them from going to either end. This established the general fact, that the central fluid was passive, being only dragged along by its contact with the principal fluid. This success led to other observations which required more steadiness than could be effected by holding the vial in the hand, and the power or capability of keeping the object in any position as long as we please, or moving it at pleasure any given quantity. Again, this vial mi¬ croscope may be so efficiently and conveniently used by lamp-light, as to require on that account that it should possess every power of motion with great steadiness, to prevent it at any time from being diverted or directed from the light. I have, therefore, with the assistance of Mr. Solly and Mr. Powell, entirely reconstructed it, so as to obtain every convenience that experience has shewn to be most desirable; and by this reconstruction, together with some small additions, it has become a general microscope, suit¬ able for viewing every kind of object. But as its ad¬ vantages will probably be best appreciated by an exami¬ nation of the instrument itself, Mr. Powell, of No. 24 Clarendon Street, Somers Town, having made a micro¬ scope on this construction for Mr. Solly, has authorised me to state that he will have much pleasure in submit¬ ting it to the inspection of the Society. Plate V. contains three views, drawn half the real size. Figs. 1 and 2 are mounted for viewing objects con-