168 THE AMERICAN MONTHLY [Jun 
a good service would be rendered if some really definite 
and permanent process, based on an understood system, 
could be formulated. 
FinE ADJUSTMENTS.—In the details of the construction 
of microscopes, as in fact in every other instrument or 
machine, there is no real finality, and each year sees the 
introduction of some slight improvement which may tend 
to make work easier and more accurate. A study of the 
catalogues of the various microscope manufacturers of a 
year or two ago will afford food for reflection, for nearly 
every noted maker then expressed his unbounded confi- 
dence in his particular form of fine adjustment. One states 
that his “‘must be considered to be a triumph of mechani- 
cal skill,” another “‘has proved absolutely satisfactory,” 
and a third “its reliability is unsurpassed.” Yet within 
the space of a few months nearly all the leading makers 
found it desirable to introduce new devices for fine ad- 
justments. All of them have distinctive features, indi- 
‘cating that care and consideration have been given to 
their design, and it will probably prove of interest to 
readers to be made acquainted with such particulars as I 
have been able to collect from the various makers, for 
‘every new idea which enables the worker to manipulate 
more precisely than available means have permitted him 
formerly to do, should receive both consideration and re- 
commendation. 
A perusal of the paper read before the Royal Micro- 
scopical Society, by Mr. E. M. Nelson, and reported in 
the Society’s Journal for August, 1899, on the “Evolution 
of the Fine Adjustment,” conveys some idea of the grad- 
ual improvement that has taken place in the movement. 
Those who use a substage condenser giving a small ap- 
lanatic cone will probably not feel the necessity of a bet- 
ter fine adjustment than that which is usually fitted to 
student’s stands having the direct pillar action. 
‘Directly an illuminating cone bearing a fair proportion 
