APPENDIX A. 



THE USE OF THE COMPOUND MICROSCOPE. 



The Instrument. — For eleiiieiitai\v class work, a lo^v-priced but 

 strong and well-made 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 AVm. Kraift, 411 AA'est Or»th St., Xew 

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

 St., Boston. The Leitz Stand. Xo. IV, can be furaished duty free 

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

 §24.50. If several insti'uments 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) 87.80. 



The American manufacturers, Bausch & Lomb Optical Company, 

 Rochester, X. Y., and Xo. 130 Fulton Street, Xew York City, have 

 this year produced a microscope of the Continental tj-pe which is 

 especially designed to meet the requirements 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 J-inch objectives, §25.60, or with 2-inch, §-inch and i-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 I^'), and 

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

 for .§20.40. Stand " A," with two eye-pieces, |-inch and -J-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 cau 

 examine the preparation of the object, the focusing of the instrament, 



