at the Magnetic Observatory at Prague. 4-25 



constant quantity. The numbers thus obtained were entered 

 in the tables, each in the column corresponding to the distance 

 of the moon from the magnetic meridian at the time of the 

 observation. From the great number of observations that were 

 in this combination, it might be expected that the effects of 

 other influences would disappear, and that of the moon alone 

 would be visible. The two horizontal elements, the declina- 

 tion and intensity, were thus treated, and the means obtained 

 for the separate months were combined in a yearly mean, 

 which is represented in the following table : — 



I. Declination in Scale-divisions, each = 27"'2261. 



Eastern 

 HoraryAngles. 



Declin. 



Declin. 



1 

 Western 

 HoraryAngles. 



12 



11-44 



11-21 



11 



13 



10-96 



10-79 



10 



14 



11-14 



11 01 



9 



15 



10-78 



10-64 



8 



16 



1076 | 



10-24 



7 



17 



10-55 



10-69 



6 



18 



10-51 



10-42 



5 



19 



10-52 



10-15 



4 



20 



10-66 



10-16 



3 



21 



10-48 



1032 



2 



22 



10-54 



10-46 



1 



23 



10-97 



10-62 







From this table we may draw the following conclusions : — 



I. If we take the sums of the declinations during the 

 eastern and during the western horary angles, we find 

 the first sum to exceed the second by 2*60 scale-divisions 

 = 70"*79 ; therefore the declination is greater when the moon 

 is east of the meridian, as already shown by the Milan obser- 

 vations. 



II. If we compare the sum of the declinations correspond- 

 ing to the horary angles from 6 h to I7 h with those from 18 h 

 to5 h , the first sum exceeds the second by 4r40 scale-divisions 

 = 119 ,,, 79; the declination is therefore greater when the 

 moon is in the neighbourhood of the inferior meridian : and 

 the table shows that it is greatest at the hour when the moon 

 is on the inferior meridian. 



III. From the comparison of the sums of the declinations 

 corresponding to the horary angles from 21 h to 2 h with the 

 sums of those from 18 h to 20 h , and 3 h to 5 h , it results that the 

 first sum exceeds the second by 0*97 scale-divisions = 26"'4l ; 

 therefore it appears that at the time of the moon's passing 

 the superior meridian, a second maximum of the declination 



