prevalent Disorders, Sf-c, "with Volcanic Emanations. 441 



falling nearly ten minutes : they were supposed to be meteors, 

 which were obscured by the brightness of the moon, being 

 only partially opaque. Now, whether these were meteors or 

 not, the occurrence is singular. It is certain, that on Aug. 4. 

 there were meteors in Hungary, with snow on the Alps suc- 

 ceeding (seeikf. 2V. H., vii. 299.) ; and on the 10th, a display 

 of meteors seen in Worcestershire (see M. N. H., vii. 386.). 

 The only thing which puzzles me in this account is, that the 

 meteors should not have brilliance enough to appear bright 

 out of the moon's disk, and yet should be opaque enough to 

 cast a shadow over it. I presume the idea of an eruption in 

 the moon is out of the question. The dew point, on the 7th, 

 was 73° ; in the night of the 8th, there was a great rain ; the 

 weather on that day was precisely the same as that of Nov. 

 12., with a westerly wind ; and on the 9th, the dew point was 

 52°. Mr. Espy thinks a vortex of downward air took place 

 s.w. of Philadelphia on that day, from the cold upper current. 

 He also concludes, that, if meteors are formed, as he has indi- 

 cated, from a northern upper cold current, containing less caloric 

 to the pound than the air below, it will account for several re- 

 markable phenomena, such as sudden cold in patches. Ex- 

 amples are furnished as follow, from the month of May 1830, 

 which I also arrange in a tabular form : — 



From these facts it would certainly appear that these aurorae 

 were low in the atmosphere, and that they were connected 

 with the sudden reduction of temperature at the times in 

 question, occurring in the same insulated manner. 



