ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 523 



Treadle— Ampnipleura (Resolving). English Mechanic, lxxix. (1904) p. 83. 



„ Diatoms (Resolving). Tom. cit., p. 84. 



„ Pinnularia nobilis (Resolution of). Op. cit., lxxviii. (1904) p. 554 ; 



Op. cit, lxxix. (1904) pp. 14, 35. 



Vill agio— Resolution of Diatoms, etc. Tom. cit., p. 193. 



(6) Miscellaneous. 



Comparison of British and Foreign Students' Microscopes.* — 

 "Paterfamilias," under the heading of "The Microscope and the Fiscal 

 Question," thus compares the London-made Microscopes with those of 

 foreign manufacture : 



Foreign Microscopes. 



Germany, Jena. In Zeiss' catalogue we find that the kind of instru- 

 ment we require, i.e. one suitable for a student, is represented by Stand 

 No. VI. a, and that its price is 12/. 10s. (The focusing of the sub- 

 stage condenser is by a sliding tube.) 



America. Messrs. Bausch and Loinb supply an instrument very 

 similar in every respect to the Zeiss for 11/. 6s. 



Italy. Koristka, of Milan, supplies a Microscope precisely like the 

 Zeiss for 10/. 16s. 



Austria : Reichert, of Vienna. The Microscope of this maker differs 

 from those preceding inasmuch as it has a lever interposed in the fine 

 adjustment action, a sliding-bar to the main stagj, screw focusing and 

 centring action to the substage. Notwithstanding these accessories its 

 price is 9Z. 15s., or 22 per cent, less than Zeiss. 



Germany : Berlin. Messrs. Leitz supply a Microscope with a bent 

 claw tripod foot and a sliding-tube focusing substage, but in other 

 respects similar to the Zeiss Microscope, for 11. 5s., or 42 per cent, less 

 than the Zeiss. 



British Microscopes. 



Messrs. 0. Baker, of Holborn, quote a Microscope with a bent claw 

 tripod foot, a differential screw fine adjustment, otherwise the same as 

 the Zeiss, for 82. 15s. Gd. 



Messrs. Swift and Son, of Tottenham Court Road, supply a Mien >- 

 scope with a fine adjustment having an interposed lever, after the method 

 of Reichert's, for 8/. 6s. In other respects it is the same as the Zeiss. 



Messrs. Watson and Son, of Holborn, quote a " Fram " Microscope, 

 having a tripod foot and a lever fine adjustment, for 81. 8s. 



These three Microscopes, of BrLish manufacture, have a sliding-tube 

 focusing substage at the price quoted. 



Messrs. Beck and Co., of Cornhill, make a " London " Microscope 

 with a screw focusing substage, otherwise similar to the Zeiss stand, for 

 11. lis., or 40 per cent, less than the Zeiss. 



In comparing the prices quoted by the various makers, we can see at 

 once that in the foreign group of Microscopes the Jena, American and 

 Italian are by far the most expensive, because they have the ordinary 



* English Mechanic, lxxxi. (19(»5) pp. 290-1. 



