APPENDIX. 



355 



TABLE XX. 



Difference in Weight of two columns of Water, each one foot high, at 



various Temperatures. 



*^* It will be observed in the above table that the amount of motive 

 power increases with the size of the pipe ; for instance, the power is 

 4 times as great in a pipe of 4 inches diameter as in one of 2 inches. 

 The power, however, bears exactly the same relative proportion to the 

 resistance, or weight of water to be put in motion in all the sizes alike ; 

 for, although the motive power is 4 times as great in pipes of 4 inches 

 diameter, as in pipes of 2 inches, the former contains 4 times as much 

 water as the other. The power and the resistance, therefore, are rela- 

 tively the same. 



