prevalent Disorders, Sfc, with Volcanic Emanations. 297 



of weather, in consequence of the highly electrical state ot 

 the atmosphere, which frequently follows such a change ; or 

 whether higher portions of the atmosphere descended, bringing 

 the meteors along with them ; or whether the meteors them- 

 selves, by disturbing the equilibrium of the atmosphere, caused 

 air from colder regions to flow into the parts where they 

 prevailed ; or, finally, whether some common and remote cause 

 is to he sought for, that gave origin to both the change of weather 

 and the meteors,^^ The present undertaking may, perhaps, 

 elucidate and explain this more probable solution of the diffi- 

 culty. Two particulars are mentioned in Silliman's Journal^ on 

 which stress is there laid, viz., the occurrence o^ tremendous gales 

 of wind between the lat. of 40° and 50° n., at the time of the 

 meteors, and the sudden change of the air from warm to cold. 

 I shall illustrate the former by powerful examples of violent 

 winds in the course of these researches ; but, for the present, 

 shall only attempt to show that cold is a common effect of 

 meteors, and also of volcanic action, I must, however, first 

 prove that the aurora is almost always succeeded by a change 

 in the direction and intensity of the wind, and of the atmo- 

 sphere. 



On the 12th October, 1833, a most brilliant aurora illu- 

 mined the atmosphere (see Mr. Fielding's paper, VII. 50.), 

 which Professor Airey has computed to have been from 50 

 to 60 miles above the surface of the earth. [Camh. Phil. 

 Trans.) Mr. Fielding has registered the remarkable changes 

 in the weather which followed this meteor, especially the 

 sudden decrease of temjperature. (VII. 51.) On the same day 

 occurred a furious gale at Madeira, and all along the coast 

 of British America. On the 13th and 14th we had, in Eng- 

 land, a very heavy gale attended with rain. Being called up 

 about 3 A.M., on the 14th, to go into Poole for a medical 

 attendant, I had the opportunity of witnessing another display 

 of auroral light, of a most interesting character. The moon 

 was but one day old, and consequently did not shine ; 

 and the sky was covered with thick masses of clouds, which 

 rushed rapidly across from the s.w. to n.e. But these clouds 

 (which would have occasioned pitchy darkness) were illumi- 

 nated by bright flashes of light, which traversed them in the 

 direction of the magnetic meridian, communicating a general 

 brightness equal to that of a clouded full moon. The night 

 was, during this display, very warm, and a soft misty rain 

 was falling; which was, however, during the darkness which 

 preceded, and all the next day, extremely violent. Captain 

 Parry [Third Voyage, p. 172.) mentions a similar phenomenon 

 seen by him in crossing the Atlantic, and names Oct. 5. 1825, 



