S22 STUDENTS’ MICROSCOPES. 
ments.* Only standard and available styles are given, by relis 
American makers, and no such makers have been intention 
omitted. The selection of instruments and apparatus of the 
ferent makers is entirely the responsibility of the writer, and 
of the makers. He has selected such sets, at the makers’ pri 
as he has been accustomed to recommend to students and ot 
for the general purposes of students’ microscopes. 
The table of Objectives is designed to be complete in regant 
American lenses, and to present for comparison, and for the 
venience of those who desire a variety of lenses by different 
makers, such European items as could be obtained at the time of 
writing. It is believed that the table will be interesting to othe 
than buyers, as showing the prevailing powers, prices, «ig 
apertures ete., in different parts of the world. N otwithstanding ti 
general impression that the prices of American objectives arë 
reasonably high, it will be seen that they compare favorably vit 
those of the most celebrated English makers. Most T 
prepare very cheaply mounted objectives of small angle, 
usually second quality, which answer a good purpose 
omy is imperative and difficult work is not required. Such lees 
are not usually priced and sold separately by the 
kers, and are therefore not included in their columns m the tabie 
objectives.t They can be obtained, however, at prices Prope” 
to their angles and quality. The prices and angular AP 
given in the table are generally, though not in every cas 0° 
up to date; but a reasonable allowance must be made for} 
variation from the standard angles and powers. There is 
of over 9 
Binoculars are furnished, when ordered, 
who do not manufacture them. 
even by © 
*Quart. Jour. Mic. Sci., Jan. 1872. opticians: 
This remark would also apply to a few of the English oP! ; 
