MAGNETIC SURVEY OP GREAT BRITAIN. 



165 



If we collect in one view the values of u and r which have 

 been obtained from the several series in Scotland, we have as 

 as follows : 



Table LXV. 



Regarding the values of u and r as entitled to weight pro- 

 portioned to the number of stations of which each is the re- 

 presentative, and giving equal weight to a result by each me- 

 tlj|d, we obtain —50° 02' and -000132 as the mean values of 

 u and r derived from the Scottish series, and corresponding to 

 the central geographical position in bQ° 40' N. lat., and 3° 30' 

 W. lonffitude. 



Section III. — Ireland. 



{By the Rev. H. Lloyd.) 

 1. Method of Vibration. 



The body of results obtained by this method in Ireland has 

 received some valuable accessions, and undei'gone other impor- 

 tant alterations, since the publication of the Irish Magnetic 

 Report. We shall consider these under the following heads. 

 1. Additional observations ; 2. Corrections of the results pre- 

 viously obtained ; 3. New determinations of the intensity at the 

 base stations. 



Additional Observations. — These consist in a comparison of 

 the intensity at London and Dublin, made by myself in the year 

 1836; a comparison of Dublin and Bangor, made by Major 

 Sabine in the latter part of the same year; a comparison of 

 London and Dublin, by the same observer, in the year 1838; 

 and a complete series of observations made by Captain James 



VOL. VII. 1838. M 



