NVJXL] 



LIEUTENANT HOOD ON THE AURORA. 



595 



The above diurnal variations were obtained by one of. Kater's Compasses, 

 which may be read within a minute by the reflecting microscope. It was 

 placed on a shelf in a room of the Expedition-house, at Fort Enterprise, and 

 close to a parchment window, which admitted the air, by several holes. No 

 ferruginous matter was near enough to affect it; but it was twice accidentally 

 moved ; and although the extent of the error thereby occasioned, was ascer- 

 tained by comparison with Mr. Franklin's observations, and those of the pre- 

 ceding days, yet their connexion is not to be fully depended on, so as to de- 

 rive from them the monthly variations. However, the intermediate periods 

 will serve to show the variation for particular days, and also the amount of 

 aberration caused by the Aurora. 



A diurnal variation evidently exists ; the maximum of which is at 9h. a. m. 

 and the minimum, at 3 or 4h. p. m. The irregularities of the needle may be at- 

 tributed to the Aurora ; because the appearance of that meteor has been so 

 much more frequent here than at Cumberland-House, where the needle was 

 not often disturbed. 



Some other opinions were inserted in this part of Mr. Hood's journal ; but 

 as they are detailed more at length in his preceding remarks on the Aurora 

 Borealis at Fort Enterprise, they are omitted here. 



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