146 * Carl Zeiss, Jena. 



Spherometer. 



Focometer, apparatus for measuring the focal lengths of 



systems of lenses. 

 Fizeau-Abbe Dilatometer. 

 Apparatus for demonstrating the optical connection between 



diffraction spectrum and the image of an object. 

 All as described in the Catalogue of Optical Measuring 

 Instruments, 1893. (German, and English editions.) 



Historical and statistical notes. 



The firm of Carl Zeiss was founded in 1846 by Dr. Carl Zeiss, 

 who died in 1888. At present upwards of 500 persons are employed in 

 the optical and mechanical workshops (incl. the foundary, joiner's shop, 

 smithy etc.) in the exclusive manufacture of optical instruments and 

 apparatus for purely scientific and fine technical purposes; viz. 

 microscopes and their accessories, photo -micrographic apparatus, photo- 

 graphic lenses and optical measuring instruments of various kinds. 



The gross value of the annual production in these goods has since 

 several years exceeded one million Marks. About one half of the goods 

 remain in Germany, the other half is for export. The latter extends 

 to all countries in and beyond Europe where scientific work is done. 



There are three departments, viz.: 



1. Microscopic and Photo-Micrographic Department. 



2. Photographic Lens Department. 



3. Department of Optical Measuring Instruments. 



These departments are under one commercial management, but are 

 each under the supervision of scientific specialists. The scientific, tech- 

 nical and commercial staff consists in all of 20 persons. There are, at 

 the present time, 3 general directors, viz. Prof. Abbe, Dr. Schott 

 and Dr. S. Czapski. 



Until 1875 Mr. Carl Zeiss was the sole proprietor of the works. 

 In that year Prof. Abbe, who had been associated with the establishment 

 since 1866, became a partner, and in 1881 Dr. Roderich Zeiss, the 

 eldest son of the founder, entered as third partner. After the death 

 of Dr. Carl Zeiss his son retired from business in 1889, and the Optical 

 Works were handed over in 1891 to the ,,Carl Zeiss Memorial' 4 in 

 Jena, which had been founded by Prof. Abbe in 1889 for the promotion 

 of scientific and social aims. 



Since the 1st July 1891 the establishment has ceased to be private 

 property. It transacts its business on account of the ,,0arl Zeiss Me- 

 morial", which is endowed with the legal powers of a person and whose 

 representative is the Government of the Grand-dukedom of Saxony. 



The Jena Glass Works (of Schott & Genossen), which are 

 affiliated with the Optical Works, having been founded in 1884 by 

 Dr. Otto Schott in conjunction with the then proprietors of the firm of 

 Zeiss, are since 1891 joint property of Dr. Schott and the ,,Carl 

 Zeiss Memorial". 



