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LIII. On the Aurora Borealis of February ISi/i^ 1837, as oh- 

 served at Sidmoitth, in Devonshire. By N. S. Heineken, Esq. 



To the Editors of the Philosophical Magazine and Journal. 



GeNTLExMEN, 



T^HINKING that some of your readers may feel an interest 

 -■• in a subject which is becoming of much importance in 

 meteorology, I am induced to forward, for insertion in the 

 Philosophical Magazine, the following account of some ob- 

 servations which I made during the occurrence of the most 

 splendid aurora borealis which 1 have ever witnessed. 

 I am, Gentlemen, respectfully yours, 



N. S. Heineken. 



At 16™ past 7 (mean time), in the eveninf^g of the 18th of Fe- 

 bruary (Saturday), I observed the commencement of an aurora 

 borealis of the most vivid pink hue, occasionally approaching 

 to scarlet. At this time the centre of the brightest part of the 

 aurora bore, by compass, about 6° north of west, allowance 

 being made for variation. At 27"* past 7 the bearing con- 

 tinued nearly the same. The altitude of the upper edge (which 

 was not well defined), taken, as near as might be, at the time 

 with a Gunter's <]uadrant, and verified afterwards with a re- 

 flecting sextant, was about 55°. At 32™ past 7 the former bear- 

 ing of the main body continued the same, but the tint had 

 now spread round to the N.E. The altitude of the brightest 

 part was from 35° to 36°, the altitude of the edge remaining 

 much as before. The stars in Cassiopeia shone through the 

 aurora (though not the most brilliant part of it) somewhat 

 more dimly than usual, and they appeared to partake of the 

 colour also, as did other stars. The thermometer stood now 

 at 434°, the barometer at 29*566. The smallest lock of white 

 cloud (cirrus?) passed over at 3"^ before 8 to the eastward : 

 at 15"^ past 8 fleecy clouds arose from the very point of the 

 ai.iora's first appearance and passed to the eastward. The 

 gold leaves of the electrometer were no^ slightly, but evidently 

 affected. 1 mention this latter circumstance (which I ob- 

 served again in the course of the evening) with some hesita- 

 tion, finding that upon several occasions in the Polar expedi- 

 tions no such indications were given. The wind, I may men- 

 tion, was now very moderate. About 9"^ before 9 the aurora 

 shifted to S.S.W.; a slight pink band appeared between 

 Rigel and Sirius ; an arch was formed of the same colour at 

 1™ before 9, edges not well defined, passing between Aldebaran 

 and >3 Orionis, over Castor and Pollux, and extending a little 

 beyond diem on either side, and, still continuing, the western- 



Third Seiies. Vol. 10. No. 61. April 1837. 2 M 



