MICROSCOPE AND ACCESSORIES 



\_CH. I 



"Tube-length" in 

 Millimeters. 



In the following tables tube-length b-d of the diagram greatly preponderates, 

 and a large majority of unadjustable objectives are corrected for a thickness of cover- 

 glass falling between fifteen and twenty hundredths of a millimeter (o. 15-0. 20 mm. ) . 

 Length in Millimeters and Parts included in the '"Tube-Length" by 



Various Opticians. 

 Pts. included 

 in "Tube- 

 length. ' ' 

 See Diagram. 



fChas. Baker, London, England 150 or 250 mm. 



The Bausch & Lomb Optical Co. , 



Rochester, N. Y 160 or 216 mm. 



R. & J. Beck, London, England 160 or 220 mm. 



Bezu, Hausser & Cie, Paris, France 180 mm. 



Klonne und Miiller, Berlin, Germany 160 or 250 mm. 



Queen & Co., Incorporated, Phila , Pa 170 mm. 



Ross, Ltd, London, England 160 or 254 mm. 



W. und H. Seibert, Wetzlar, Germany 170 mm. 



Swift & Son, London, England 160 or 228 mm. 



Watson & Sons, London, England 160 or 250 mm. 



R. Winkel, Goettingen, Germany 192 mm. 



[Carl Zeiss, Jena, Germany 160 or 250 mm. 



f Ernst Leitz, Wetzlar, Germany 170 mm. 



| Nachet et Fils, Paris, France 160 mm. 



j Powell & Lealand, London, England 254mm. 



I C. Reichert, Vienna, Austria 160-180 mm. 



| Spencer Lens Company, Buffalo, N. Y 160 mm. 



[ W. Wales, New York 254 mm. 



The Gundlach Opt. Co., Rochester, N. Y. 254 mm. 



E. Hartnack, Potsdam, Germany 160 mm. 



Dollond & Co., London, England 165, 240 mm. 



Ve"rick (Stiassnie) Paris, France 160-200 mm. 



P. Wachter, Berlin-Friedenau, Germany 160 mm. 



J. Zentmayer, Philadelphia, Pa, i6oor235tnm. 



Cover-Glass for Which Non-Adjustable Objectives are Corrected by 



Various Opticians. 



f The Bausch & Lomb Optical Co., Rochester, N. Y. 

 J Klonne und Miiller, Berlin, Germany, 

 j Queen & Co., Incorporated, Philadelphia, Pa. 

 [The Spencer Lens Co., Buffalo, N. Y. 

 f Ernst Leitz, Wetzlar, Germany. 

 I P. Wachter, Berlin-Friedenau, Germany. 

 I R. Winkel, Goettingen, Germany. 



(Chas. Baker, London, England. 

 R. & J. Beck, Ltd., London, England. 

 Gundlach Optical Co., Rochester, N. Y. 

 W. und H. Seibert, Wetzlar, Germany. 

 E. Hartnack, Potsdam, Germany. 

 C. Reichert, Vienna, Austria. 

 Ross, Ltd., London, England. 

 Verick (Stiassnie), Paris, France. 

 ( Carl Zeiss, Jena, Germany. 



J. Zentmayer, Philadelphia, Pa. 

 J Dollond & Co., London, England. 

 \ Nachet et Fils, Paris, France. 



Be"zu Hausser & Cie, Paris, France, 

 f Powell & Lealand, London, England. 

 \ Swift & Son, London, England. 

 Watson & Sons, London, England. 

 W. Wales, New York. 



FIG. 24. 

 Thickness of 



o. 18 mm. 

 0.17 mm. 



0.15 mm. 



0.15-0.18 mm. \ 



0.15-0.20 mm 



0.12-0.17 mm 

 0.10-015 mm. 

 0.10-0.12 mm 

 o.io mm. 



0.20 mm. 

 0.25 mm. 



