OF OPTICAL INSTRUMENTS. 103 



in view, that the high refinements of the most costly, are hy no means essential for the 

 interesting practical investigations of the chemist or physician ; who are often unwilling 

 to incur an outlay that is cheerfully expended on the highest refinements of powers or 

 the elegant arrangement embodied in instruments for presentation. 



BEST COMPOUND MICROSCOPES, 

 WITH MUCH IMPROVED EXTKA WIDE BAB TO RACK-WOEK. 



FIRST SEEIES. 



1107. Superior Large Compound Microscope, of latest improved construction, 



with long divided draw tube, bar motion, extended to work with 4-inch, 

 objective, improved thin goniometer stage /or oblique light, divided to 360 

 degrees, with 1-inch, rectangular motion and best object-holder with spring 

 clip, the whole stage being worked round by means of a rack and pinion, con- 

 centric with the axis of the object glass. The fine adjustment is of the best 

 lever construction, with divided milled head for correcting the objective to the 

 thickness of glass covering the object, improved sub-stage, with rotary motion 

 and rectangular adjustment divided to 360 degrees, especially adapted for 

 correctly centering the illuminating apparatus, with plain and concave mirrors, 

 on jointed arm for oblique light illumination, improved expanding diaphragm, 2 

 Heugenian eye-pieces, A and B, and eccentric clamp for fixing the instrument 

 at any inclination required (fig. 1107), p. 102 29 10 



1108. If in polished mahogany cabinet, with 3 drawers, packing, etc., complete, extra 



2 12 6 



1109. Or, in best Spanish mahogany case, with mouldings, extra . 3 15 



1110. The above microscope, with Wenham's binocular arrangements, with divided 



draw tubes and 2-inch, rack and pinion motion for adjusting to different 

 widths of eyes, and 2 extra eye-pieces, A and B . . 35 10 



The binocular part of this instrument is so arranged that the bodies can be readily 

 removed so as to use it either as a binocular or monocular instrument of the very finest descrip- 

 tion, price, if so arranged with both bodies .... 37 10 



1112. Superior Large Compound Microscope, with divided draw tube and improved 



thin compound stage, having rotating plate, object -holder, and 1 inch, of 

 motion in rectangular directions, best lever fine adjustment (similar to the 

 preceding), sub-stage with rotating wheel divided to 360 degrees, and complete 

 adjustments for centering illuminating apparatus, plain and concave mirrors, 

 on double -jointed arm for oblique illumination, improved expanding diaphragm 

 and 2 eye-pieces, A and B (fig. 1112), p. 104 . . 23 10 



1113. If in polished mahogany cabinet, with 3 drawers, packing, etc., complete, extra 



2 5 



1114. Or, in best Spanish mahogany case, with mouldings, extra . 330 



1115. If with Wenham's binocular arrangement, similar to No. 1110, with suitable 



additional eye-piece, extra . . . . . 6 10 



1116. Superior Microscope Stand, as above, but of smaller size, with f -inch rectangular 



motions to stage, rotating plate to thin top stage, object clamp and best lever 

 fine adjustment, complete sub-stage, double jointed arm to mirrors, diaphragm, 

 and 2 eye-pieces, A and B . . . . . 17 10 



1117. If with Wenham's binocular arrangement with 1^-inch. rack and pinion motion to 



draw tubes, and 1 additional eye-piece, extra . . 550 



