THE MICROSCOPE. 93 
brass, without glass or mechanical 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 isa 
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 curved 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 
