144 



EIGHTH REPORT — 1838. 



Table XLV. — (cotitinueil). 



Omitting Dublin, which has been transferred to the Irish 

 section, and taking a mean of the three resuks at Tortington 

 for the intensity at tliat station, we have here twenty sta- 

 tions in Britain to be combined by the method of least 

 squares : whence x= + -000048 ; y = - -000062 ; ti = — 5^ 

 27'; r = -000078; and/= 1-0075, the probable value of the 

 intensity at the mean geographical position, of which the lati- 

 tude is 52° 36', and the longitude 2° 1 1'. 



Professor Phillips's observations. — ^These were made with 

 a needle on Mr. Lloyd's statical principle, employed in Mr. 

 Phillips's six-inch circle. The needle had been recently re- 

 ceived from the maker (Robinson), when it was first used at 

 York in June 1837; and the results obtained with it on the 

 3rd and 5th June, compared with those on the 15th June, indi- 

 cated that its magnetism had not become steady. To obviate 

 this inconvenience as far as might be possible, Mr. Phillips re- 

 peatedly, during the series of his detei-minations, brought the 

 needle back to York, and re-examined its magnetic state. 

 We are thus furnished with observations at that station in 

 June, August, September, October, 1837, and in February, 

 1838, which are arranged in Table XLVI., and show the pro- 



