36 On the prevailing Siorms of the Allantic Coast. 



In the same latitude, Lon. 70° 30', " tremendous gale," com- 

 mencing at south-south-east, and veering to north. 



At New York, and on Long Island Sound, the gale was at north- 

 north-east and north-east, on the afternoon and evening of the 17th. 



Off Nantucket shoals, at 8, P. M. the gale commenced severe at 

 north-east by east. 



In the gulf stream, oft' Nantucket, in Lat. 38° 15', Lon. 67° 30', 

 on the night of the 17th, " tremendous hurricane," commencing at 

 south, and veering, with increasing severity, to south-west, west, and 

 north-west. 



At Elizabeth island, Chatham, and Cape Cod, (Mass.) the gale 

 was severe at north-east, on the night between the 17th and 18th. 



On the 18th, heavy gale from north-east, at Salem and Newbury- 

 port, Mass.) 



Early on the 18th, in Lat. 39° 51', Lon. 69°, severe gale from 

 south-east, suddenly shifting to north. 



In Lat. 41° 20', Lon. 66° 25', "tremendous hurricane" from 

 north-north-east on the 18th of August. 



On the night of the 18th, off" Sable island, and near the Porpoise 

 bank, in Lat. 43°, Lon. 59° 30', " tremendous heavy gale " from 

 south and south-west to west, and north-west. 



In Lat. 43°, Lon. 58°, severe gale from the south, the manner of 

 change not reported. 



This remarkable storm appears to have passed over the whole rout 

 comprised in the foregoing sketch, in about six days, or at an ave- 

 rage rate of about seventeen geographical miles per hour. 



The duration of the most violent portion of the storm, at the seve- 

 ral points over which it passed, may be stated at from seven to 

 twelve hours. 



The general width of the track influenced in a greater or less de- 

 gree by the gale, on the American coast, is estimated to have been 

 from five to six hundred miles. 



Width of the hurricane portion of the track, or severe part of the 

 gale, one hundred and fifty to two hundred and fifty miles. 



Semi-diameter of the hurricane portion of the storm seventy five 

 to one hundred and twenty five miles. 



Rate of the storm's progress from the island of St. Thomas to 

 Providence Island, Bahamas, fifteen nautical miles per hour. 



Rate of progress from Providence to St. Johns, Florida, sixteen 

 miles per hour. 



