280 



Photometric Obnert'ations of the Sun and Sky. 



The effect of the faint fog in increasing the value of [V] = [W] 

 is plainly seen in the morning observations. The effect also of a 

 very few faint fleecy clouds is seen in the increase of [V] and of 

 [U] for the observations at l h O m and l h SO, before which no clouds 

 had been visible. The air was saturated the whole day. 



The candles which I used in all these observations, were the 

 " Belmont Sperm," supplied to me so as to burn 100 grs. in 47 

 minutes. 



