38 THE REGISTER. 



month, without which his labor would run the hazard of losing 

 its value. 



Barometer. The degree of the attached thermometer and the 

 observed height of the barometer will be inscribed in the first 

 two columns. This height will be reduced to freezing-point, or 

 32 Fahrenheit, or zero Centigrade, by means of tables, and the 

 whole correction of the instrument will be applied to it. It will 

 then be inscribed in the third column, entitled corrected height at 

 freezing-point. These corrected heights, and never any others, 

 must be employed to form the mean, which will be inscribed in 

 the fourth column. 



Thermometer. In the thermometrical observations the quan- 

 tities above zero will be always written without a sign ; the ne- 

 gative quantities will be all individually marked with the sign 

 minus ( ), whether they follow each other or are isolated. In 

 the first column, entitled daily mean, will be inscribed the mean 

 of the three observations of the day, i. e. their sum divided by 

 3, admitting two decimals. 



Psychrometer. In the first two columns will be entered the 

 indications of the dry and wet thermometer, after having applied 

 to each of them the correction of the instruments, if there be 

 any. By means of the psychrometrical tables will be found the 

 force of the vapor and the degree of relative moisture, each of 

 which has its column. 



We have indicated above the manner of noting the direction 

 of the winds. 



As to the force of the surface wind, which alone can be esti- 

 mated with some degree of precision, it will be expressed by 

 adding to the letter which designates the direction, the figure 

 indicating its force: e. g., N, without a figure, signifies a slight 

 air, hardly perceptible, coming from the north; N t , a slight 

 breeze; N 3 , a strong wind, &c. The other two columns will 

 have only letters, or a dash ( ) if the observation has not been 

 possible. 



The quantity of clouds, or the cloudiness estimated from zero, 

 or a perfectly clear sky, to 10, sky entirely overcast, has a sepa- 

 rate column. 



It is the same with rain and melted snow, which will be sepa- 

 rately entered. A third column is reserved for the total quantity 



