XXI. England. — Greenwich. Lat. 51° 29' N. ; Long. 0° 0'. 

 Corrections to be applied to the Means of the Hours of Observation, or Sets of Hours, 

 to obtain the true Mean Barometric Pressure for the respective Months. — Glaisher. 



Engliah Inches. 



D 



The numbers without sign must be added : those with the sign — must be subtracted. 



94 



