1S92.] MICKOSCOl^ICAL JOURNAL. 137 



troducing new optical glasses of high refractive indices and in the 

 creation of the apochroinatic objective. The exhibit included a 

 large varietv of the well-known Zeiss stands, with their different 

 classes and powers of oculars and objectives, and their outfit of 

 numerous and ingenious accessories ; also a special stand for pho- 

 tomicrography, a complete special photomicrographical apparatus 

 that is small and portable, and another of great size furnished 

 with a Schuckert electric lantern and the most elaborate appur- 

 tenances of various kinds. But the most interesting feature of their 

 exhibit was a demonstration of the construction of a large stand 

 and of an aprochromatic objective and a compensating ocidar. 

 All the pieces entering into tlie construction of a No. i stand 

 were displayed spread out in a case, like a picture against the 

 wall, each piece being given in duplicate, once in the rough cast- 

 ing or section of tube or wire, and again in the finished form 

 ready for assembling into the completed instrument. In another 

 case were superb blocks of the new optical glasses of Drs. Abbe 

 and Schott of Jena, and of the fluorite of the Oltscheren Alp. 

 The different stages in the construction of an S mm. apochro- 

 matic objective and of a compensating ocular were also dis- 

 played in proper series, all the lenses entering into the combina- 

 tion being shown both in the rough and the finished state. 

 Probably every visitor would have voted with the jury in awarding 

 the one special j^rize, the diploma of pre-eminence, to the Jena 

 company. 



Next to this, three grand prizes were given, which went to 

 London, Paris, and Germany, respectively. The English one 

 was bid for by a solitary stand, with two or three objectives and 

 condensers at its feet, that looked so lonesome, not to say insig- 

 nificant, that to claim a leading prize for it seemed almost pre- 

 sumptuous. Its appearance, amidst the neighboring cases 

 crowded with showy apparatus, suggested at once the quiet home 

 from which it came in Euston Road, in contrast with the showy 

 shops where such goods are commonly'displayed. But the stand 

 made a strong competition for its not too modest claim, to be the 

 most perfect that is made, the apochromatic objectives were judged 

 to merit their high reputation, and the apochromatic condensers 

 were found to give a singularly perfect illumination, and a '•'•grand 

 prix " was awarded to Powell & Lealand. 



Prizes of like grade were well earned by, and awarded to, A. 

 Nachct of Paris, and to E. Hartnack, originallv also of Paris, but 

 since the Franco-German war, now of Pottsdam, Germany, both 

 of whom exhibited a large variety of apparatus of the very highest 

 grade, including excellent apochromatic objectives and sumptu- 

 ous photomicrographic apparatus. 



Of the many creditable exhibits of a somewhat more modest 

 grade, at least in respect of prices, by far the largest was that of 

 Wm. Watson & Sons, of London. In fact, it was one of the most 

 interesting and commendable features of the exposition. It stood 



