152 * Mr. G. M. Minchin. [May 16, 



The glare from, the moon was now very distinctly apparent, and 

 its effect seemed to be a deflection of about O5 mm., which must be 

 deducted from Saturn's effect. This latter would, then, be repre- 

 sented by about 3'25 mm., or a voltage of O009. 



Tluj next observations were made on the night of Friday, the 12th, 

 and on this night the atmosphere was very hazy, although many 

 stars were visible. It is not necessary to enter into the details of 

 observations on such a night ; nevertheless, it may be interesting to 

 see the effects which were observed. 



For the following bodies the mean deflections were as tabulated : 



Jupiter 6'33 mm. 



Cygni 0-50 



Vega 2-26 



Arcturus 2'50 



Regulus 1-10 



A standard candle placed at a distance of 9 feet from the cell pro- 

 duced a deflection of 11 mm. 



Nothing of a quantitative nature can be deduced from these results 

 owing to the presence (and unequal distribution) of haze, the effect 

 of which was to make Vega produce a deflection less than that of 

 Arcturus. 



On the night of the 14th the sky was clearer, and while Arcturus 

 gave a very fairly constant deflection of 4*5 mm., Regulus gave 

 T85 mm., e Bootis O32 mm., Coronse 0'6 mm., and ft Herculis 

 something less than 0'2 mm. 



The night of the 15th was, for a short time, much clearer, and 

 during this time the following more reliable measures were made: 



Arcturus 8'2 mm. (mean of 4 observations) 



Saturn 5'6 ,, ( ,, 4 ) 



Vega 11-5 ( 2 ) 



Candle at 9 feet. . lO'O 



Leclanche cell . . . 513'0 ,, 



It would be interesting to compare the intrinsic energies of 

 Arctnrus and Vega, but the parallax of Vega seems to be almost 

 more uncertain than that of Arcturus. It is given in Young's 

 ' Astronomy ' as 0*16, while Miss Clerke gives Elkin's value as 

 " 0-034 ?" If the first of these is taken, with the value 0*018 for 

 Arcturus, equation (4) gives the intrinsic energy of Arcturus equal 

 to 38'2 times that of Vega; but if the second is taken, this number 

 becomes only 1*8. 



