Ciresson.) 296 [December. 



Prof. Cresson made some remarks upon the great fall of temper- 

 ature that occurred the day previous to the meeting, accompanied by 

 a sudden rise of the barometer, similar to that observed on the 7th 

 and 8th of January of this year, when these phenomena were ex- 

 hibited over a large extent of territory, embracing all the Northern 

 and Middle States of the Union. 



He also described a curious effect of the extreme cold, observed 

 by him this morning in Schuylkill County, where the thermometer 

 stood at 15° below zero of Fahr. Just after daybreak he saw the 

 steam thrown off by the large engines of a colliery rising in a verti- 

 cal column of dense cloud some 300 feet or more in height, and then 

 float off horizontally from the top of the column in a stratum some 

 two or three miles long, where it rested, without much change of 

 level, for a long time. 



The phenomenon being, in his opinion, the result of the sudden 

 freezing of the vesicular mass and the entanglement in it of a quan- 

 tity of air, of which the temperature was so much higher than that 

 of the surrounding atmosphere, to keep the whole afloat, as he sup- 

 posed to be the case in most of the lofty mackerel clouds. 



The Committee of Finance made tlieir report, and recom- 

 mended the usual appropriations for the expenses of the So- 

 ciety during the ensuing year, which were adopted. 



Pending nominations Nos. 552 to 567 were read. 

 And the Society was adjourned. 



