THE NATURE AND 



[SECT. 11. 



94. The next point is to compare the formula with experiment ; and we shall 

 commence with Mr. Watt's experiments on salt water. The water was nearly 

 saturated with salt : it was more free from air than common water, but it parted 

 with difficulty from that which it contained. The results compared with the 

 formula for saturated salt are shown in the following table. 



WATT'S EXPERIMENTS ON THE STEAM FROM SALT WATER. 



In these, as in all the early experiments on the force of steam, the force is less 

 than it ought to be at low temperatures. 



Mr. Watt's experiments on pure water afford a like discrepancy, as will be found 

 by comparing the following table of results taken at random out of his series. 2 



WATT'S EXPERIMENTS ON PURE WATER. 



rated water from the bottom, or lower part of the boiler, by means of a pump, and subsequently by 

 means of their blow-off pipes and cocks, now generally followed : the operation of blowing off is 

 usually attended to every three or four hours. 



1 The results in this column are calculated by the Rule I, by logarithms, given at page 59, with 

 this difference, that instead of subtracting 2-24797 as for common water, the number 2-26703, as 

 given in the preceding table, is used for saturated solution. 



2 Robison's Mechan. Phil. vol. ii. p. 3234. 



