APPENDIX A. 



THE USE OF THE COMPOUND MICEGSCOPE. 



The Instrument. — For elementary class work, a low-priced but 

 strong and well-ma^e instrument is needed. Several of the German 

 makers furnish excellent instruments for use in such a course as that 

 here outlined. The author is most familiar with the Leitz micro- 

 scopes, which are furnished by Wm. Krafft, 411 West 59th St., New 

 York City, or by the Franklin Educational Co., 15 and 17 Harcourt 

 St., Boston. The Leitz Stand, No. IV, can be furnished duty free 

 (for schools only), with objectives 1, 3, and 5, eye-pieces I and III, for 

 $24.50. If several instruments are being provided, it would be well 

 to have part of them equipped with objectives 3 and 7, and eye-pieces 

 I and III. The best form of camera lucida for this microscope costs 

 (duty free) $7.80. 



The American manufacturers, Bausch & Lomb Optical Company, 

 Rochester, N. Y., and No. 130 Fulton Street, New York City, have 

 this year produced a microscope of the Continental type which is 

 especially designed to meet the requireihents of the secondary schools 

 for an. instrument with rack and pinion coarse adjustment and 

 serviceable fine adjustment, at a low price. They furnish this new 

 stand, « AAB," to schools and teachers at " duty-free " rates, the prices 

 being, for the stand with two eye-pieces (any desired power), |-inch 

 and ^inch objectives, $25.60, or with 2-inch, |-inch and |-inch objec- 

 tives, and two eye-pieces, $29.20. 



Stand " A," the same stand as the " AAB," without joint and 

 with sliding tube coarse adjustment (as in the Leitz Stand TV), and 

 with three eye-pieces and |-inch and J-inch objectives, is furnished 

 for $20.40. Stand " A," with two eye-pieces, |-inch and ^-inch objec- 

 tives, $20.40. 



Class Use of the Microscope If the class works in a special 



laboratory in small divisions (not more than twelve), the teacher can 

 examine the preparation of the object, the focusing of the instrument, 



