40 RECORD AND DISCUSSION OF TEMPERATURES. 



note, Oct. 19th, 1854, it appears that the numbers expressive of the quantity of 

 solar light have the following signification : 



1 Entirely clear. 



2 Slightly obscured. 



3 Clouded. 



4 Misty and dark. 



5 Excessive obscurity. 



The sign 0, which occasionally occurs, probably indicates either no observation, 

 or snowy or rainy atmosphere. There are a few apparent anomalies in the follow 

 ing tables, the temperature indicated by the black bulb being somewhat lower than 

 that indicated by the shade thermometer with an overcast sky. These may arise 

 from a slightly erroneous index error, or occasional observing errors, or different 

 localities of exposure. 



The following record of the observations of the temperature by the black bulb 

 thermometer exposed to the solar rays, contains the corrected readings, which ren 

 ders them directly comparable with the readings of the preceding general record, 

 and has been inserted for the use of those who may desire to further investigate 

 the subject. 



