22 HOW TO USE THE MICROSCOPE 



tion of one eye-piece and two objectives, giving 

 power from x 59 to x 270, the price is £5 3s. 6d. 



I consider Messrs. Watson's " Praxis " microscope 

 (Fig. 5) to be one of the cheapest on the market. 

 It is sound in construction, good in all its details. 

 It is conspicuous for compactness, lightness, and 

 portability, combined with complete steadiness and 

 entire absence of vibration. For the stand only, 

 fitted with coarse and fine adjustments, plane and 

 concave mirrors, condenser fitting, draw-tubes, and 

 ebonite covered stage, the list price is £3 15s. 

 Possessing such a stand, the beginner can add eye- 

 pieces, objectives, and accessories as needed, and 

 may consider himself the o\^Tier of an instrument 

 which will do excellent service and bear hard usage. 

 I also recommend the "Fram " stand (Fig. 9), made 

 by the same enterprising firm ; it is a high-class 

 mstrument, marketed at the low figure of £4. I 

 find it particularly suitable for photo-micrography ; 

 indeed, it was used in the production of the photo- 

 graphs illustrating this volume. 



The " Portable Clinical and Field Microscope," 

 made by Messrs. James Swift and Son, London, is 

 held in high regard by many naturalists, particu- 

 larly as it can be packed very compactly in a leather 

 case, and is thus easily portable. This instrument 

 is strong in build. It has a draw-tubo with milli- 

 metre scale, mirror, and substage fitting. The stand 

 with one eye-piece, in leather case, with accommoda- 

 tion for two objectives, etc., is fisted at £5 (see 

 Fig. 10). 



The instruments mentioned above are a few 

 selected out of many that are on the market. I 



