THE MICROSCOPE. 93 



brass, without glass or raechanical attachments. The tube is 

 usually supported by an arm or bar and the coarse adjustment 

 is effected by means of a sliding tube. The fine adjustment 

 on all foreign instruments which the author has seen has in- 

 variably been well made and moves the arm and with it the 

 tube. The English model is larger and much more compli- 

 cated and clumsy. The base is usually of the " tripod form 

 and the uprights supporting the working parts are much taller 

 than is necessary. In the higher priced instruments the 

 stage usually bears a plate of glass which in turn supports 

 the object. This glass stage, theoretically, is a great conven- 

 ience as it affords a very smooth motion and preserves the 

 working parts from corrosive liquids ; but in practice it is a 

 great nuisance and can well be dispensed with. The stage 

 in most of the English models is larger than in the continen- 

 tal and in this respect is better. The tube is generally sup- 

 ported by a cur\'ed arm and the coarse adjustment effected 

 by rack and pinion. The fine adjustment indifferently moves 

 either the whole tube or just the nose-piece, many manufac- 

 turers making both styles. The tube itself is almost always 

 unnecessarily long and this defect is increased by a draw 

 tube. When English and American students learn that defi- 

 nition is better than amplification, and that the shorter an 

 instrument is, the better and more useful it is, then, and not 

 till then, may we hope for a change for the better in this re- 

 spect. It may seem out of place in a work of this character 

 to speak of one instrument in higher terms than of another, 

 but there are many who wish to purchase microscopes who 



