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THE ROYAL SOCIETY OF CANADA 



The pressure was obtained from a Fortin barometer, and the true 

 temperature of steam calculated. The true fundamental interval 

 was then given by the formula 



100 (Rb-Ro) 



F.I. 



B 



where B is the calculated temperature of steam. 



When the iron and the platinum thermometers were compared, 

 each was connected to a separate key in the circuit, so that either could 



IG 



2. 



be quickly placed in the bridge. A pail of water, heated by a gas burner 

 and stirred by a screw paddle, constituted the temperature medium. 

 This could be adjusted to undergo a slow steady rise or fall or tempera- 

 ture at any point between 0° and 100°. To compare the two, measure- 

 ments were made on the platinum thermometer at two definite times, 



