Beck, on the Universal Achromatic Microscope. 11 
Diagram 2 the table turned over, the upper part folded 
3. 
as a fan ; one wheel taken out, and its corner disjointed ; 
the middle bar, with its connecting wires. The dotted lines 
mark the holes to which each wire of the wheel and centre 
pivot belongs. 
A Description of the Universal Achromatic Microscope, as 
continved and manufactured by Smith, Beck, and Beck. 
(Read Oct. Otb, 1861.) 
The word cheap, when applied to the achromatic micro- 
scope, by no means loses its varied and comprehensive mean- 
ing. As manufacturers, Ave are not unfrequently told by the 
gentleman who has paid his hundred guineas for his in- 
strument that he does not consider it expensive, but cheap, 
compared with the instruction and amusement it affords, 
or, indeed, as nothing, when contrasted with an indulgence in 
many other tastes ; whereas, on the other hand, we receive 
a letter from an inquirer for a cheap microscope, in which, 
after stating its numerous qualifications, we are told we must 
on no account exceed the sum of 10^. 6c?. 
Now, disregarding these extremes as well as ^' the happy 
medium^^ (for our price is much nearer the smaller sum), 
we still claim the title of cheap for the microscope which is 
represented in Plates V and VI. 
At first sight, the instrument undoubtedly appears one- 
sided, and to those who are inclined to form an opinion as to 
its deformity, we must confess that, after a most careful 
