348 



M. H. C. Vogel on the Absorption of the 



sheets of paper were again exposed during 30 and 40 seconds. 

 The numbers given in the following Table were calculated by- 

 taking the mean of four observations, which were taken by de- 

 termining the intensity on four points at equal distances from 

 the sun, and situated on two diameters at right angles to each 

 other. 



Distance from centre. 







Intensities. 



Radius =54. 







1000 



4 



1000 



14 



98-9 



24 



94-3 



34 



78-5 



40 



700 



45 



53-9 



47 



40-0 



49 



32-6 



51 



28-6 



53 



187 



In the first days of the month of May numerous observations 

 were made on photographs taken in the focus of the large equa- 

 torial instrument, which have only a diameter of 45*4 millims. 

 In order to be able to compare these observations with those just 

 given, I have assumed their radius to be 



54, 

 54 



and reduced the 

 The numbers 



observations by multiplying them with 



given are the means of eight observations on six photographs 



Distance from centre. 



Intensities. 



Radius =54. 



00 

 11-9 



23-8 

 357 

 47-6 

 51-6 

 528 



1000 

 98-3 

 930 

 780 

 499 

 220 

 14-5 



On the 5th of May a magnified photograph was taken, and 

 the relative intensity was measured on points lying symmetri- 

 cally from the centre on a diameter. The diameter of the pho- 

 tograph was 102*9. The tints were compared with two scales 

 prepared at different times. 



