39 



CONTENTS. 



(The figures refer to the folio at the bottom of the page.) 



PRACTICAL TABLES BASED ON REGNAULT'S HYGROMETRICAL CONSTANTS. 



a. In French Measures. 



Page 



TABLE I. Elastic Force of Aqueous Vapor, by Regnault .... 9 



" II. Psychrometrical Tables, by Haeghens ..... 12 

 " III. For deducing the Relative Humidity from the Indications of Dew- 



Point Instruments, by Haeghens ...... 30 



1 00 

 " IV. Factor -p- for computing Relative Humidity .... 36 



" V. Weight of Vapor contained in a Cubic Metre of Air . . .38 



b. In English Measures. 



" VI. Elastic Force of Vapor, reduced from Regnault's Table . . 43 



" VII. Psychrometrical Tables, by A. Guyot 46 



" VIII. For deducing the Relative Humidity from the Indications of Dew- 

 Point Instruments, by A. Guyot ...... 75 



" IX. Factor -, , for computing Relative Humidity .... 90 

 " X. Weight of Vapor in a Cubic Foot of Saturated Air ... 94 



PRACTICAL TABLES BASED ON THE HYGROMETRICAL CONSTANTS ADOPTED IN THE 

 GREENWICH OBSERVATIONS. 



TABLE XI. Elastic Force of Aqueous Vapor . . . ... 101 



" XII. Psychrometrical Tables, by Glaisher .104 



" XIII. Factors for computing the Force of Vapor from Psychrometrical 



Observations, by Apjohn's Formula ..... 140 



" XIV. Factors for finding the Temperature of the Dew-Point from the 



Readings of the Psychrometer ...... 142 



" XV. Weight of Vapor contained in a Cubic Foot of Saturated Air . 143 

 u XVI. Factors for deducing the Weight of Vapor from the Indications of 



Dew-Point Instruments ........ 143 



" XVII. For comparing the Weight of a Cubic Foot of Dry and of Satu- 

 rated Air 144 



" XIV. Fnctors for finding the Temperature of the Dew-Point from the 



Readings of the Psychrometer . . . . . . 146 



3 



