94 



CONSTRUCTION OF THE MICROSCOPE. 



FIG. 16. 



from about five to forty diameters, is obtained. The stage is 

 perforated with a hole at each corner; into any one of which may 



be fitted a condensing 

 lens for opaque objects 

 ( 64), or a pair of 

 stage-forceps ( 66). An 

 aquatic-box for the ex- 

 amination of objects in 

 water ( 68) is also sup- 

 plied. 1 This instrument 

 is peculiarly adapted for 

 educational purposes ; 2 

 being fitted in every 

 particular for the ex- 

 amination of botanical 

 specimens, small insects 

 or parts of insects, water 

 flies, the larger animal- 

 cules, and other such 

 objects as young people 

 may readily collect and 

 prepare for themselves ; 

 and such as have 

 trained themselves in 



Field's Simple Microscope. ^llC application of it 



to the study of Nature, are well prepared for the advantageous 

 use of the Compound Microscope. But it also affords to the 

 scientific inquirer all that is essential to the pursuit of such 

 investigations, as are best followed out by the concurrent em- 

 ployment of a Simple and a Compound Microscope, the former 

 being most fitted for the preparation, and the latter for the 

 examination, of many kinds of objects; 3 and it may be easily 

 adapted to the purposes of dissection, by placing it between arm- 

 rests ( 104), or blocks of wood, or books piled one on another, so 

 as to give a support for the hand on either side, at or near the 

 level of the stage. 



30. Quekett's Dissecting Microscope. To the scientific investi- 

 gator, however, it is generally more convenient to have a larger 

 stage than the preceding instrument affords ; and in this respect 

 an arrangement devised by Mr. Quekett (Fig. 17) will be found 

 extremely convenient. The stage, which constitutes the princi- 

 pal part of the apparatus, is a plate of brass (bronzed) nearly six 

 inches square, screwed to a piece of mahogany of the same size 

 and about fths of an inch thick ; underneath this a folding flap 



1 The price of the instrument, with all these appurtenances, packed in a neat ma- 

 hogany box, is only half a guinea,- and the maker, Mr. G. Field, of Birmingham, is 

 bound by his agreement with the Society of Arts to keep it always in stock. See also 

 31. 



2 See Introduction, pp. 60, 01. 3 See Introduction, p. 63. 



