Bernhard Halle, Berlin. A. Hasemann, Berlin C. 17 



No. 2760. 



Bernhard Halle, Steglitz nr. Berlin. 



Speciality: Optical appliances for polarization of light etc. 



Preparations of Island double spar: Polarizing prisms. These 

 are made in numbers by a process invented by the exhibitor. By means 

 of a special sawing machine designed by Mr. Halle great accuracy of 

 the angle is obtained; by means of fine polishing appliances the surfaces 

 and angles are further reduced to absolute exactness; the prisms are of 

 the highest degree of perfection; nevertheless the prices are extremely 

 low and compete successfully with those of any other firm. 



Beside these, quartz preparations of all kinds are made of the 

 highest perfection. Glass prisms without pyramidal errors, prisms 

 and plates of rock salt, alum, tourmaline etc., made in the most 

 accurate manner. 



The trade supplied on liberal terms. 



No. 2761. 



A. Hasemann, Berlin C., 



7 & 8 Nicolai Kirchhof 



Maker of Balances. 



This factory produces principally balances of best quality with 

 beams suspended in the center. 



Exhibited balances: 

 1. A set of official assize balances Nos. i to 4. 



Sensibility expressed according 



No. Maximum charge to the directions of the German 



Assize Department. 



1 50 kilos 1/50000 



2 5 1/20000 



3 1 kilo 1/20000 



4 20 grammes 1/4000 



(These balances are among the instruments exhibited by 

 the Imperial Assize Commission.) 



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