452 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



the data of each of the five piezometers, is shown in Table II., together 

 with the weighted means. Finally, the deviation of the weighted 

 mean from a parabolic formula is plotted against pressure, and a 



TABLE I. 

 Data for Compressibility of Water at 0°. 



smooth deviation curve drawn. In only two instances does the smooth 

 deviation curve fail to pass through the points of the weighted mean. 

 The value given by this smooth deviation curve is to be taken as the 

 final value, and is also given in Table II. The change of volume is to 



