681 



COUPvECTIONS 



FOR 



FORCE OF VAPOR AND RELATIVE HUMIDITY. 



HOURLY CORRECTIONS FOR PERIODIC VARIATIONS, 



OR 



TABLES 



FOR REDUCING THE MEANS OF THE OBSERVATIONS TAKEN AT ANY HOUR OF THE 



DAY TO THE TRUE MEAN FORCE OF VAPOR AND RELATIVE HUMIDITY 



OF THE DAY, OF THE MONTH, AND OF THE YEAR. 



117 



