MAGNETIC SURVEY OP GRKAT BRITAIN. 



85 



A correction is therefore required of— 9' 6 to all the dips 

 observed with S 2. The application of this correction pro- 

 duces the final column in Table XVIII., entitled " Corrected 

 Dips." 



In Tables XVIII. and XIX., we have, then, the dip observed 

 at fifteen stations with Gambey, and at four additional stations 

 with S 2, making in all nineteen stations, which are inserted 

 in the following table with their geographical positions, and the 

 dips reduced to the mean epoch of the observations themselves, 

 viz. the 1st January, 1838. 



Table XX. 



Combining these by the method of least squares, we 

 obtain the following values: .r=-f2305; y=— '498; 

 M=— 65° OS'; r = -548; and 8 = 69° 56'-6 at the mean geogra- 

 phical position, of which the latitude is 52° 18', and the longi- 

 tude 1° 59'. 



If now we collect in one view the several values of u and r 

 which have been thus obtained from the observations in Eng- 

 land, we havd as follows : 



Table XXI. 



