908 SEC. 18. BIOLOGY. 



3548. Student's Microscope in an alloy of German silver 

 and aluminium. James Sivift. 



3550. Microscopes. G. S. Wood. 



3551. Microscope with complex adjustments, searcher, and 

 oblique condenser apparatus. Dr. Royston-Pigott, F.R.S. 



This microscope is fitted with a peculiar hypocycloidal movement and tra- 

 versing screws for very delicate observations. The condenser possesses wide 

 rectangular movements combined with a unique oscillating oblique action for 

 directing the minute image of a flame or the sun either directly or obliquely 

 upon any desired point in the field of view, giving fine views of many difficult 

 objects, and gorgeous diffraction phenomena with circular solar spectra. It 

 is also fitted with Dr. Royston-Pigott's searcher for aplanatic images, by 

 which much greater depth of focus is attained, and new powers of correcting 

 chromatic and spherical aberration, by moving the searcher between the 

 objective and the eye piece or ocular. 



3552. Improved Microscope, with rotating body. 



John Browning. 



This instrument is contrived so as to combine the advantages of the English 

 with the continental models ; it is especially adapted for dissecting purposes, 

 as the body rotates with the stage ; objects may be examined with any power 

 without losing their centricity. 



3553. Stephenson's Binocular Microscope. 



John Browning. 



In this instrument, for the first time, the planes introduced by Mr. Ste- 

 phenson for altering the direction of the ray, so that the microscope can be 

 used with the stage in a horizontal position, have been introduced near the 

 eyepiece in the separate bodies ; this arrangement will, it is believed, be found 

 to possess considerable advantages. With Stephenson's binocular, objects 

 may be examined with both eyes with the highest objectives. 



3554. Microscope with Micro-Spectroscope. 



John Browning. 



The micro-spectroscope is intended for the observation of absorption bands 

 in the spectra of solids or fluids, either by reflected or transmitted light. The 

 instrument exhibited contains Mr. Sorby's most recent improvements. 



3555. Pocket or Field Microscope, 'with two achromatic 

 object glasses, contained in a leather case, measuring 7 X 3 X If in. 



John Browning. 



3556. New Portable Microscope. John Browning. 

 This powerful and complete instrument, fitted with a sub-stage, accessory 



apparatus, polariscope, &c., is contrived to fold on a hinged joint in such u 

 manner that when set up it is the size of an ordinary microscope, but when 

 closed, it packs in a case of which the outside measurement is 6 x 6 x 9. 



3556a. Field Naturalist's Microscope. 



Washington Tcasdale. 



The field naturalist's microscope was designed by the exhibitor specially to 

 meet the difficulty of teaching, and making generally popular, the use of the 



