242 Miscellaneous Intelligence. 



falls to the ground ; and that downward currents set through those 

 flues, at the bottom of which there is no fire ; and it is supposed 

 that when this takes place in a town, it occasions the fogs 

 peculiar to those accumulations of houses. Many instances are 

 then quoted, according with these views, but M. Arago objects 

 to the conclusion, remarking, that, in the first place, these fogs 

 often form in a few minutes ; and in the next, that they frequently 

 do not occur in the calmest, and according to M. Defranc's sup- 

 position, most favourable, weather. — Ami. de Chimie^ xxxiii. 415. 



5. Atmospheric Phenomenon ; Ohio, U.S. — The following effect 

 is described by Mr. Atwater ; *' Before a storm here I have often 

 noticed in an evening of the latter part of Autumn, and some- 

 times in the winter, a phenomenon not recollected by me to have 

 been seen on the east side of the Alleganies. Some one spot 

 or spots near the horizon, in a cloudy night, appeared so lighted 

 up, that the common people believed there was some great fire 

 in the direction from which the light came. I have seen at once two 

 or three of these luminous spots not far from each other ; generally, 

 there is but one, and a storm, invariably proceeding from the same 

 point near the horizon, succeeds in a few hours. — SillimaiV s Jour- 

 nal, xi. 226. 



6. Effects of Cold. — The following natural temperature, and its 

 effects, which occurred at Marietta, in the state of Ohio, are re- 

 corded by Dr. Hildreth, of that place. Feb. 9th, 1818, at 7 A.M., 

 Fahrenheit's thermometer sunk to 20° below zero. On the 10th, at 

 half-past 6 A. M., it was down to 22° below zero, in the open air, 

 and suspended to the limb of a tree. With all this severity of cold, 

 the Ohio river was not frozen across ; it was full of floating ice, 

 and during the night and morning of the 9th and 10th, threw up a 

 continual cloud of vapour, which darkened the air ; and freezing 

 as it ascended, fell again in a moderate shower of snow. So in- 

 tense was the cold, that there was a continual cracking and 

 snapping, by the contraction of wood in buildings and in trees. 

 Very strong brandy, exposed in a tea-saucer to the open air, 

 through the night of the 9th, was found frozen to ice the next 

 morning. The weather was colder at this time, by ten or twelve 

 degrees, than has been known since the country was first inhabited." 

 — Silliman's Journal xi. 232. 



7. Notice of Mr. BurchelVs Travels in South America. — It will be 

 gratifying to our scientific readers to know that, notwithstanding the 

 liberal encouragement given by the continental governments to 

 researches in South America, some portion of the harvest will be 

 reaped by this country, by the enterprise and unassisted exertions of 

 her scientific sons. Mr. Swainson explored the provinces on the 

 north-east coast of that vast empire a few years ago. But a far 

 more interesting and hazardous journey is now performing by Mr. 



