96 Schott & Genossen, Jena. 



No. 2786, 



Schott & Genossen, Jena. 



Olasteclmisches Laboratorinm. (Glass Works.) 



Optical Glasses and Glass-tubing for Thermometers etc. 



The Glass Works of Schott & Genossen in Jena were founded 

 in 1884 .and had their -origin in a laboratory for scientific experiments 

 in glass smelting. The first investigations made in 1883 and 1884 by 

 Dr. Otto Schott in conjunction with Prof. Abbe, and later experiments 

 on a manufacturing scale, in which they were liberally supported 

 financially by the Prussian Government, resulted in the production of a 

 series of glasses beside the ordinary Crown and Flint glasses of the new 

 Baryta, Phosphate and Borate series, which led the way to the con- 

 struction of improved optical instruments. We may mention among 

 these: Improved microscope objectives of the ordinary (achromatic) series,. 

 Apochromatic microscope objectives and apochromatic photographic 

 lenses, Improved Aplanatic lenses (envolving the use of Baryta glasses), 

 the Anastigmatic lenses recently constructed by Carl Zeiss and 

 Telescopes with diminished secondary spectrum. 



The application of a very accurate process of annealing enables the 

 glass-works to produce pressed lenses and large objective discs free 

 from internal strain. 



The Laboratory produces also special glasses for scientific and 

 technical purposes: 



Tubes of the ,,Jena Standard Glass" (registered trade-mark: 

 One red line) with diminished secondary thermal effect and minimised 

 variability of the zero-point, for fine and accurate thermometers. Glasses 

 of a very high and also very low coefficient of expansion. Combustion 

 tubes and tubes for Explosion furnaces. Compound tubes for Water- 

 gauges, consisting of two glass layers of different expansive powers 

 fused together, capable of resisting, in a high degree, sudden changes 

 of temperature and the corrosive action of water. 



The Laboratory is prepared to compound and smelt such special 

 glasses which are calculated to lead to improvements. 



Exhibits : Discs for Telescope Objectives, polished slabs of Optical 

 Glasses (ordinary Crown glasses, heavy and heaviest Baryta -Crown 

 of high refractive power, Crown glass of high and low dispersion, Phosphate 

 and Borate glasses free from silica, Baryta light flints, ordinary Flint 

 glasses with refractive powers up to 1.9), moulded and annealed lenses 

 for the Zeiss Anastigmatic and other photographic lenses; Prisms for 

 total reflection. - - Jena standard glass-tubes, Borosilicate glasstubes, 

 Combustion-tubes, Tubes for Explosion furnaces and Compound Tubes. 



