684 XCIX. 



ENGLAND. GREENWICH. Lat. 51 29' N.; Long. 0'. 



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

 to obtain the true Mean Humidity for the respective Months. (GLAISHER.) 



Thousandths. 



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



120 



