IV 
PREFACE. 
We are daily receiving inquiries from persons who desire 
information and advice in regard to the selection of micro- 
scopes adapted to their particular purposes. It frequently 
happens that persons making these inquiries have had but 
little opportunity to become acquainted with the theory and 
uses of microscopes made in the most recent and improved 
style. Properly to reply to all these inquiries would absorb 
too much of our time, which we desire to devote exclusively 
to the more delicate and important labor of our art. We 
have therefore decided to publish in our catalogue such infor- 
mation as shall enable every one to understand the philosophy 
and structure of the most improved microscopes, and to jndge 
of the qualities of different microscopes that may be offered 
to their patronage. 
So rapidly has the microscope been improved within a very 
recent period, that instruments which were made but a few 
years since have become of little value, compared with the 
improved achromatic miscroscopes which are now made by 
the best opticians of England and America. 
This rapid advance of improvement has caused a large stock 
of microscopes of inferior quality to be thrown into the market 
at very low prices, and those who are not aware of the great su- 
periority of the achromatic microscope, as at present con- 
structed, are induced to purchase cheap, but inferior^ instru- 
ments. With this species of trade it is not our purpose to com- 
pete. But to those who desire to obtain microscopes of the best 
construction, combining the most recent scientific improve- 
ments and fitted for the prosecution of the highest order of sci- 
entific inquiries, we offer our microscopes with confidence that 
wherever their merits are known they will give ample satisfac- 
tion to purchasers. 
J. & W. Grunow & Co. 
Kew Haven, Conn., Oct. 1, 1857. 
