ON THE SPECIFIC HEAT OF WATER. 



209 



thence up outside the jacket-tube and out by the exit tube e. By this means the 

 inflow water is effectively shielded from heating by the obturator. The level of the 

 top and bottom of the obturator in relation to the inflow is indicated by f and g in 

 fig. 3. 



For the outflow there is provided a tube L furnished with a side branch V. The 

 tube L is closed at the Iwttom, except for a small hole S, and has an opening at the 

 top which is closed by a cork R, through which passes the thermometer W, which 

 indicates the outflow temperature. The bulb of this thermometer is adjacent to the 

 orifice S through which the water passes to the outflow. Instead of taking the 

 outflow through S direct from the main body of water in the calorimeter, it is taken 

 through a bent tube T immersed in the water for two reasons. In the first place, 

 the surface of the water is a good deal agitated by the stirrer, so that the tube T 

 provides a small space in which an undisturbed surface can be maintained. In the 

 second place, by causing the outflow to travel through the tube T a steady outflow 

 temperature is more easy to maintain. It should be noted that the tube L jackets 

 the lower part of the thermometer where it passes through the obturator and into 

 the air, so that the thermometer could be read in the condition of being immersed to 

 the level of the cork R. The reading point on the scale of the thermometer was just 

 above the top of tube R. This arrangement secured true readings of this ther- 



/vVWVV 



Fig. 4. 



mometer from calibration when immersed to the same level. A thermometer placed in 

 the side branch V showed that the temperature of the water after it had passed 

 through the tube L was practically the same as at the outflow point S. 



From the tube V the outflow water passed by gravity through a tube of 

 convenient length to the weighing flask X, which was placed upon a block on an 

 adjacent table. 



VOL. ccxr. A, 



2 E 



