BECK'S ECONOMIC MICROSCOPE. 77 



" For ordinary pathological, physiological, and botan- 

 ical investigations, many of the delicate adjuncts applied 

 to the higher-priced instruments are unnecessary, and 

 tend rather to contuse than to assist the beginner." 



To this let these pages say again, Amen. 



" A firm stand and well-corrected object-glasses are, 

 however, indispensable." 



In response to this we not only say amen, but shall, 

 in the proper place, have something further to add. 



"The stand of the "Economic" is made in two 

 forms: the one with a sliding adjustment for focussing 

 the object, and the other where the quick movement is 

 produced by rack and pinion. On both stands the fine 

 adjustment is given by means of a milled head at the 

 top of the stem. The stand is fitted with the society 

 screw. 



The foundation of the stand is a heavy horseshoe 

 base A, at the head of which is a firm pillar B, having 

 at its top a hinge joint C, which allows the body D to 

 be inclined to any angle, and is sufficiently firm to per- 

 mit of its beins: placed horizontal for use with the 

 camera lucida. 



The body tube is short, but by means of the length- 

 ening draw tube V can be made of the standard length. 



In the more expensive stand the coarse adjustment is 

 by rack and pinion; in the cheaper instruments the 

 quick movement is produced by sliding the body D up 

 and down the tube H, sliding over the inner stem with 

 a spring inside, the fine adjustment being accomplished 

 by the milled head I. 



