194 



PROCEEDINGS OF THE AMERICAN ACADEMY 



Table III. 



Observations in Table II., arranged according to the Amount and 

 the Sign of the Differences. 



30.237 

 30.117 

 30.197 

 30.147 

 30.327 

 30.127 

 30.137 

 30.537 

 30.107 

 30.397 

 30.367 

 30.147 

 29.907 



Mean, 30.212 

 " 30.048 



Difference, .164 



Table IV. 



1849, Sept. 10. The aneroid stood at 30.39. It was placed under 

 the receiver of an air-pump, and the atmospheric pressure diminished 

 by five inches. When the air was admitted, the index moved forward to 

 30.35. It rose to 30.375 in two or three minutes. The following 

 table embraces similar experiments, with their results. 



