of certain Winds and Storms. 29S 



rcction for Uventy-four hours. The average velocity of the 

 wind during these storms never exceeds this estimate of forty- 

 four feet per second, — probably it never reaches it*. The result 

 will be simply that of bringing the air overhanging the eastern 

 part of Maine, and that overhanging the south-western part of 

 Georgia, into contact with each other over the state of Maryland. 

 The effect would be gradually produced, but the total amount 

 would be the same throughout the whole length of the Atlantic 

 coast, with that arising from an instantaneous application of the 

 under stratum of the air resting upon the Maine, to the upper 

 stratum of air resting upon Georgia. But this would be alto- 

 gether inadequate to the determination of a fall of snow several 

 inches in depth, and of weather at the same time intensely cold. 

 It is also to be remarked, that there is often almost a calm 

 when the rain or snow commences. It is only gradually that 

 the wind makes itself felt and rises to a gale f . 



3. There are good reasons for doubting whether there be any 

 considerable transfer of the air from the north-east towards the 

 south-west, during the prevalence of a north-east storm. Sup- 

 pose a source of heat and rarefaction to exist over the Gulf of 

 Mexico ; that the air overhanging it ascends ; that the air of 

 Georgia on the Carolina side comes in to serve its place, and the 

 whole line of the Atlantic coast is affected by the drain esta- 

 blished in the south-west quarter. We might look for the fol- 

 lowing results. The wind would be most violent in Georgia, 

 and would continue to prevail there, until the cause of heat and 

 rarefaction was removed from over the Gulf. In the States more 

 remote, the wind would be feeble in proportion as the distance 

 was greater, and in Maine would be hardly felt at all. The 

 storm would cease when the cause by which it was produced 

 had ceased to act, and at nearly the same time throughout the 

 whole tract of country swept by it. The simplest doctrine of 

 equilibrium as applied to elastic fluids, force these conclusions 

 upon us. But the storm is found in fact to be as violent at the 

 north as at the south. It proceeds and is over in Georgia, and the 

 sun is perhaps shining there at the time when it is exerting its 

 utmost fury in Maine. 



• See the different tables of the velocity of the wind. 

 + Vide Mitchell's account of the NE. storm of February 1803, in the 

 Philosophical Magazine, vol. xlii. p. 273. 



