C. A. Steinheil Sohne, Miinchen. 105 



Gel-many 86.59% Brought forward 90.83% 



Austria-Hungary . . . 13.94% Switzerland 2.84% 



France 12.62% Great Britain 2.11% 



Italy 8.23% Holland 1.59% 



Eussia 7.84% Denmark 0.99% 



America 4.63% Sweden and Norway . 0.78% 



Spain and Portugal . 3.58% Turquey and Greece . 0.45% 



Belgium 3.40% Asia and Australia. . 0.31% 



Carry forward 90.83% Africa 0.10% 



100.00% 



The continuous growth of the establishment necessitated the erection 

 of a new building plant, and on ttie 1st. March 1890 the business was 

 transferred to the new premises situated outside the town (viz. in 

 Theresienhoehe). The building occupies an elevated and isolated po- 

 sition and is provided with excellently light workshops and testing 

 rooms; among the latter there are a spacious experimental studio and 

 a testing corridore of 40 meter length. The establishment is fitted 

 throughout with low pressure steam warming pipes. The plant includes 

 a number of new machines by means of which objective lenses up to 

 1 meter in diameter may be produced. 



The establishment employs about 50 men within its own precincts 

 and besides a number of others working in their own workshops. It 

 will shortly complete the 40th thousand of astronomical and photo- 

 graphic objectives. 



Photographic Apparatus and Instruments. 



Photographic Objectives. 



Antiplanetic Lenses: German Patent No. 16354, 13. April 1881. 

 British Patent No. 1602, 12. April 1881. 

 U. S. Patent No. 241437, 10. Maij 1881. 



This type consists of two entirely different parts having greatest possible 

 .aberrations of opposite sign. This plan resulted in a considerable reduction of 

 astigmatic aberration and, thereby, in uniform extension of definition and depth 

 over an increased and strictly flat area of the field. 



The two pairs of lenses, the anterior one of which is positive while the 

 posterior is negative, are placed as near together as possible. The object of 

 this close proximity is uniform distribution of brightness over the entire field. 

 The great brilliancy of the antiplanetic lenses renders them particularly 

 adapted for portrait, group aud instantaneous photography and also for exposures 

 with artificial light. At the same time, these lenses have been computed in 

 such a manner as to render them capable of producing strictly flat and correctly 



