160 Hartmann & Braun, Bockenheim- Frankfort o. M. 



No. 1349. 

 Group 123. 119. 



Hartmann & Braun, 

 Bockenheim -Frankfort o/M. 



Scientific Instruments and Electrical Apparatus. 



(150 Employees and Steam power of 36 kilowatt) 



Silver medal, Paris 1881. Gold medal, Turin 1884. 



Silver medal, London 1885. Gold medal, Antwerp 1885. 



This firm is exhibiting in a separate room situated at the 

 exit of the German Division on the Ground Floor of the Electri- 

 city Building. This room contains a fully equipped laboratory, in working 

 order, suitable for an electrical research laboratory, a central lighting 

 station or for an extensive electrical manufacturing concern ; also a collection 

 of measuring apparatus for workshop use, for electrical fitting and cable 

 laying, amperemeters and voltmeters, resistance apparatus, electrical 

 measuring instruments for continuous and alternating currents: finally, 

 a collection of electrical and magnetic instruments of precision. 



In the centre of the room. 



1. Appliances for measuring resistances of 0.01 to 11 million 

 ohms, consisting of a universal resistance bridge with plug connections, 

 reflecting galvanometer with reflecting magnet and reading telescope. 



2. Apparatus for measuring current strengths and E. M. F.'s 

 by the compensation (Null) method, consisting of a Clark standard cell 

 and ballast resistance, resistance box for main and shunt circuits, a branch 

 resistance of 0.01 ohm, an aperiodical reflecting galvanometer with 

 Siemens' bell magnet and reading' telescope. 



