SPECIFIC HEAT OF AMMONIA. 



331 



Voltage drop across the armature was kept constant 

 during a measurement by a sliding rheostat. Four bladed 

 copper churn mounted in bearings inside of container to 

 stir ammonia and distribute heat by conduction. Stirring 

 shaft insulated from calorimeter by asbestos board plug. 

 Upward thrust on stirring shaft taken by ball socket thrust 

 bearing at upper end of shaft. 



CALORIMETEFl 



COPPER LEADWIRE5 

 FILLING PLUG 

 5TEELTHRU5T BEARING 

 GLASS TUBING 

 STIRRING SHAFT 

 BRASS TUBING 

 ASBESTOS BOARD 

 SUPPORTING ARMS 

 BRASS ENCLOSING VESSEL 

 VACUUM FLASK. 

 STEEL CALORIMETER TUBE 

 —STEEL HEATING COIL SHEATH 

 MERCURY 

 LIQUID CONTAINER 

 COPPER CHURN 

 BRASS RING 

 COPPER GASKETS 

 HEXAGONAL NUTS 

 STEEL THERMOMETER SHEATH 

 FELT CUSHION 

 FINS FOR STIRRING MERCURY 



CMS. 



Figure 3. 



Heating Coil. 



Manganin resistance coil, built into calorimeter. Enclosed 

 in flattened steel sheath, 3 mm. thick, 8 mm. wide, and 

 240 mm. long. Heater introduced heat equally at all 

 levels. Supported from asbestos board cover by steel 

 brackets. Described more fully below. 



