428 HENRY A. ROWLAND 



Around these movable paddles were the stationary paddles, consist- 

 ing of five rows of ten each. These were attached to the movable 

 paddles by bearings,, at the points c and Jc, of the shaft, and were re- 

 moved with the latter when this was taken from the calorimeter. 

 When the whole was placed in the calorimeter, these outer paddles were 

 attached to it by means of four screws, I and m, so as to be immovable. 



The cover of the calorimeter was attached to a brass ring, which 

 was nicely ground to another brass ring on the calorimeter, and which 

 could be made perfectly tight by means of a little white-lead paini 

 The shaft passed through a stuffing-box at the bottom, which was 

 entirely within the outer surface of the calorimeter, so that the heat 

 generated should all go to the water. The upper end of the shaft 

 rested in a bearing in a piece of brass attached to the cover. In the 

 cover there were two openings, one for the thermometer, and the 

 other for filling the calorimeter with water. 



From the opening for the thermometer, a tube of copper, perforated 

 with large holes, descended nearly to the centre of the calorimeter. 

 The thermometer was in this sieve-like tube at only a short distance 

 from the centre of the calorimeter, with the revolving paddles outside 

 of it, and in the stream of water, which circulated as shown by the 

 arrows. 



This circulation of water took place as follows. The lower paddles 

 threw the water violently outwards, while the upper paddles were pre- 

 vented from doing so by a cylinder surrounding the fixed paddles. 

 The consequence was, that the water flowed up in the space between 

 the outer shell and the fixed paddles, and down through the central 

 tube of the revolving paddles. As there was always a little air at the 

 top to allow for expansion, it would also aid in the same direction. 

 These currents, which were very violent, could be observed through 

 the opening's. 



The calorimeter was attached to a wheel, fixed to the shaft db, by 



