Association for the Advancement of Science. 465 



a surface. Actual observation showed that in many places it was 

 not so, and this non-perpendicularity was generally referred to ir- 

 regularities of surface. If, as everything led them to believe, the 

 earth was originally in a state of fusion from heat, all the strata 

 of equal density of the fluid mass would be surfaces of equilibrium. 

 Following out the theory, the paper went on to show that if it 

 could be ascertained what was the form of the outer surface of the 

 earth's solidified crust, and the distribution of the water' over it, 

 they might be able to determine whether changes of internal struc- 

 ture took place within the earth subsequent to the formation o' 

 that crust. Observations showed that such internal changes had 

 taken place, and consequently that the direction of gravity might 

 have changed. 



Major-General Sabine on the Amount and Frequency of the 

 Magnetic Disturbance and Aurora at Point Barrow, on the Shores 

 of the Polar Sea, The lecturer stated that his results were derived 

 from observations made by Captain Maguire and the officers of the 

 Plover, between July 1852 and July 1854. Point Barrow is situ- 

 ated on the most northern coast of America. Tables made on a 

 large scale were used, exhibiting the variations with and without 

 the disturbances at different hours of the day at Point Barrow and 

 at Toronto. The horizontal force of the earth at Toronto was about 

 double what it was at Point Barrow. It was found that when the 

 disturbances were greatest in amount, the greatest displays, which 

 he considered a magnetic phenomenon, took place. The last let- 

 ter he had received from Sir John Franklin expressed that navi- 

 gator's determination to put up instruments for the observation of 

 those phenomena at the several stations at which he might winter 

 It could not be doubted that such obervations were made and 

 recorded with the instruments they took for that purpose. It 

 could not be doubted that when they were detained at some point 

 the following year they carefully made the observations, and it was 

 possible they might have even extended them to another winter. 

 These observations were numerous, and were of such a kind as 

 would have been left in the ships when the explorers proceeded 

 overland. When he (General Sabine) was with Captain Parry 

 in 1848, they made observations as to the figure of the earth, and 

 various other matters, on their way to Behring's Straits. They 

 were exposed, to considerable risk of the ships being lost, and 

 when about to take to the boats and proceed overland, they merely 

 carried with them an abstract of the observations, leaving the full 



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