88 



EIGHTH REPORT — 1838. 



Table XXIII. contains the latitudes and longitudes of Captain 

 Ross's Scottish stations, and the mean dip at. each station at 

 the dates slionn in the preceding table. The whole interval 

 in which they are comprised is so short, that no reduction 

 to a common epoch has been applied. 



Table XXIII. 



If we combine these ten results by the method of least 

 squares, we obtain the following values : x = + "250 ; 

 ^=-•484; n=-62°39'; r=0'-545; and 8=72°40'-8 at the 

 mean geographical position 57° 20' N., and 3° 08' W., and at 

 the mean epoch August 18, 1838. 



Major Sahines Observations. — These observations were 

 made at twenty- seven stations in the summer of 1836, with a 

 circle by Nairne and Blunt, and the needle S 2 of Robinson. 

 The details have been already published in the 5th vol. of the 

 Reports of the British Association, and need not therefore be 

 repeated in this place. When that Report was published, the 

 correction of S 2 was provisionally taken as —12'; it has since 

 been more correctly ascertained to be — 9'*5 bj?^ a much more 

 extensive series of comparative observations; (Table XIX.) The 

 subjoined table (XXIV.) contains the latitudes and longitudes of 

 the twenty-seven stations, and the dips, to which the new correc- 

 tion of — 9''5 has been applied. As the whole of these obser- 

 vations were comprised within an interval of six weeks, no 

 reduction to a mean epoch has been thought necessary. 



