APPENDIX. 147 



observations. Mr. Wales, astronomer to Captain 

 Cook's ship, the Resolution, had made the same ob- 

 servations in a pretty accurate manner ; and M. 

 Entrecasteaux, though without assigning any cause, 

 says, that the " Compass showed differences of se- 

 veral degrees in variation at sea, though observed 

 with the greatest care, and within the space of a few 

 minutes." 



After a more enlarged series of observations shall 

 have been taken, and after the attention of astrono- 

 mers is directed to this fact, we may confidently ex- 

 pect a most important improvement in the science 



of navigation. 



No. V. 



The following article, " on the tremendous 

 concussions of the fielus of ice," in the Arc- 

 tic Sea, is extracted from Mr. Scoresby's valuable 

 Memoir on " Polar Ice" in the Wernerian Society's 

 Transactions. 



" The occasional rapid motion of fields, with 

 the strange effects produced on any opposing sub- 



h % 



