Pliotometric Observations of the Sun and Sky. 



279 



present some haze, visible or invisible, that affects the readings of 

 the chemical action on sensitised paper very largely, even to 50 per 

 cent. 



The octant observations, the intensities estimated on the first of 

 the above strips, are as follows : 



Table K. 



The values of [V] = [W], being so much greater than I expected, 



d me to imagine that, though the sky was apparently clear, the 



observations might have been affected by the hygrometric state of 



the atmosphere. There had been a fog in the morning, and the air 



J, though translucent, saturated all the afternoon, 

 he next day, the 14th October, was a similar day (fog in the 

 morning), and I commenced octant observations much earlier in the 

 morning. The results are given in the following table: 



Table L. Octant Observations, 14th October, 1890. 





VOL. XLIX. 



