MAGNETICAL OBSERVATIONS IN SCOTLAND. 119 



ranted by the observationB recorded in this paper. Accordingly, 

 the line passing through the central station, and making with its 

 meridian an angle of 46° 15''5, is designated simply as unity for 

 Scotland; and the other lines, at intervals of 32*29 geographical 

 miles, are entitled + -015, + -010, + '005, —-005, - 'OlO, —'015, 

 according to the values of the intensity which they represent 

 relatively to the central line. 



The difference between the deductions in Ireland and in Scot- 

 land, in regard to the isodynamic lines, is considerable, and 

 apparently too great to be supposed due to an actual difference 

 in the lines themselves. It will probably be elucidated by future 

 observations. 



