3GG BEXJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



attached to an extra stage-plate, one set of three achro- 

 matic object-glasses, condenser with arms to support from 

 stage-plate, fluid-cell, dissecting instruments, pair of for- 

 ceps, and three test-objects. Price $25.00. 



Microscope, same as above, but having 3^ inch base, 

 3 inch stage-plate, and one extra eye-piece of greater 

 power. Price $35.00. 



Microscope, same as last, with the addition of the move- 

 able stage, D. Price $45.00. 



Microscope, with 3j-inch base, 2f-inch stage-plate, 8- 

 inch compound body, 3 eye-pieces of different powers, 2 

 sets of achromatic object-glasses, condenser with arms to 

 support from stage-plate, fluid-cell, dissecting instruments, 

 forceps, 3 test-objects, moveable frame below stage-plate, 

 camera lucida, and polarizing apparatus. Price $75.00. 



Microscope, with 4-inch base, 3-inch stage-plate, 8-inch 

 compound body, 3 eye-pieces, 3 sets of object-glasses, con- 

 denser on brass foot, fluid-cell, dissecting instruments, 

 forceps, 6 test-objects, micrometer, moveable frame, H, 

 below stage-plate, and moveable stage-plates, D. 



Price $85.00. 



Microscope, same as last, with the addition of the cam- 

 era lucida, and polarizing apparatus ; this instrument in- 

 cludes all the parts and appendages described, fig. 790. 



Price $105.00. 



Microscope, same as the preceding, but extra large 

 size, 5-inch base, 4-inch stage-plate ; extra part with 

 prism to incline eye-piece, and one additional set of three 

 achromatic object-glasses. Price $135.00. 



Microscopes of Ross's, and-Smith and Beck's, more ex- 

 pensive constructions, from $150.00 to $200.00. 



The Equatorial Telescope. The equatorial instrument 

 is intended to answer a number of useful purposes in prac- 

 tical astronomy. Besides answering the general purposes 

 of a quadrant, a transit instrument, a theodolite, and an 

 azimuth instrument, it is almost the only instrument 

 adapted for following the stars and planets in their ap- 

 parent diurnal motions. Many of these instruments are 

 somewhat complicated, and very expensive. The author 

 to supply the wants of his many patrons, has constructed 

 the following instruments, which may be purchased at a 

 moderate cost. They may be made use of in any steady 



