I. MICROSCOPES. 765 



5. Identity of illumination in each tube. 



6. The use of the highest powers by the projection of the prisms beyond 

 the body of the instrument into the objective. 



354Oa. New Binocular Microscope. Henry Crouch. 



This instrument has a concentric rotating stage provided with adjustments 

 for centering to the highest powers that can be applied. The sub-stage is also 

 of new construction, being detached from the stand by means of a horizontal 

 slide, and leaving the space underneath the stage entirely clear for greater 

 convenience in tha use of ordinary oblique illumination. 



354Ob. Newly arranged Binocular Microscope. 



Henry Crouch. 



This is of somewhat similar construction to the above, but not so expensively 

 finished ; with and without sub-stage. 



3540c. New Educational Microscopes for Botanical 



and Histological Work. Henry Crouch. 



3540e. Students 9 (Monocular) Microscopes of Old and 

 New Pattern. Henry Crouch. 



3541. Student's Microscope. 



James Hoiv $ Co., London. 



3542. Popular Binocular Microscope. 



James Hoiv $ Co., London. 



3542a. Microscope Lamp. James How fy Co., London. 

 3542b. Tate's Air Pump. James How $ Co., London. 



3542c. Selection of Transparent Photographs, for the 

 Lantern, illustrating lectures upon geology, consisting of sections 

 of strata, groups of fossils characteristic of the various sedemen- 

 tary formations, restorations of extinct animals, &c. 



James How $ Co., London. 



3543. "Educational Microscope." With two object 

 glasses, two eye-pieces, condenser, &c., in mahogany box. Suitable 

 for biological, histological, and physiological research. 



M. Pillischer. 



3544. Student's " or " Educational Microscope." 



With three object glasses, three eye-pieces, condenser, polarising 

 apparatus, animalcule cage, stage-forceps, &c., in mahogany case. 

 Suitable for clinical and biological research, &c. M. Pillischer. 



3545. " New College Microscope." James Swift. 



In this microscope the optical tube slides through a fitting lined with velvet 

 for smoothness of action. The fine adjustment has direct central movement, 

 and is so constructed as not to be deranged by constant use. The diaphragm 

 is flush with the surface of the stage, thus leaving the tube-fitting free under- 

 neath for the use of apparatus, and, if required, a diaphragm can be used in 

 conjunction with apy of the stage accessories. 



