420 Preliminary Report to Committee on Solar Physics. [Mar. 9 r 



that were a considerable number of years so treated, more exact valuer 

 \jexhibiting the law would be obtained. The law itself is sufficiently 

 obvious in each of the two years now treated. 



10. It has still to be ascertained to what extent the two fluctuations, 

 when brought together so that similar phases coincide as nearly as 

 possible, show any distinct resemblance to each other. 



The evidence on this point is given by the diagrams which accompany 

 this paper. These contain curves representing the continuous progress 

 of the two sets of fluctuations for the years 1871 and 1872, these being 

 /^"portioned out into months. The temperature-range curve has a 

 uniform time scale. The declination -range curve is pushed forward 

 by a distance derived from the last column of Table V. Thus for 

 January of each year it is pushed forward eight days, for February of 

 each year five days, and so on. The consequence of this is that the 

 declination -range scale, while constant for the various portions of the 

 same month, yet varies slightly from one month to another. 



An inspection of the curves will show that there is a considerable 

 likeness between them. Perhaps this likeness is greater in the second 

 than in the first year, but it must be borne in mind that 1871 was a 

 year of great magnetic disturbance, and therefore unfavourable for 

 such a comparison. 

 |~ It would thus seem as if a comparison of magnetical and meteoro- 

 logical weather might" be made a promising subject of inquiry, besides 

 • ^ being one which may perhaps lead to results of practical importance. 



Before concluding I beg to thank Messrs. William Dodgson and 

 Alfred Nish for the assistance which they have rendered in this 

 investigation. 



