394 OBSEEVATIONS ON THE CURRENTS. 



In August the Gulf Stream, also, is not represented from its origin to 

 lat. 35° N. From 35° to 40° N., and between 75° and 55° W., it appears 

 to be strong, the rates varying from 12 to 56 miles. In the same latitudes, 

 between long. 45° and 30° W., there is decided evidence of a Southerly set. 



In September it is traceable from lat. 30° N., long. 80° W., at 72 miles a 

 day, to 38° N., 63° W., at 31 miles. Between 60° and 70° W. it does not 

 appear to extend farther South than about 37° N. 



In October it passes through the Straits of Florida at 37 miles per day, 

 but the observations are deficient in number. 



In November, to the East of Florida, it has a rate of 70 to 53 miles ; 

 in lat. 34° N., it is 46 miles. Elsewhere there are no data. 



In December the Gulf Stream is well shown from long. 87° to 67° W. 

 In its South-Easterly flow to the "West of Florida its rate is from 10 to 20 

 miles. East of Florida it flows due North, at from 50 to 54 miles. 

 Thence to lat. 38° N., in its North-Easterly course, it maintains the rate 

 of from 38 to 58 miles. 



The Arctic Current, between the Gulf Stream and the coast, has been 

 frequently experienced, its rate being from 10 to 15 miles. It may be the 

 pressure of this cold water which causes the remarkable increase in the 

 rapidity of the Stream about lat. 37° N. 



(385.) Action of the Wind. — In the Strait of Florida, within the 

 Bahamas, the wind probably retards or accelerates the Velocity. A N.E. 

 gale in the Atlantic will probably bank up the water of the Stream, 

 lowering its Velocity materially, and afterwards the flow will by reaction 

 be greatly increased over the normal speed. There is no evidence of any 

 change in the position of the axis due to the wind in the Strait. 



Variations in atmospheric pressure in the Gulf of Mexico also cause 

 a considerable retardation or acceleration of the current. 



"When a Northerly gale, increased to a storm, opposes the Stream in its 

 course, this adverse power causes it to fill all the channels and openings 

 amongst the Martyr Isles and Reefs, and to overflow all the low coast. 

 Shipping have even been carried over the low kays, and left dry on shore. 

 During these times, Florida Strait exhibits a scene beyond description. 



In September, 1769, there was an inundation, which covered the tops of 

 the highest trees on the Cayo Largo, &c., and during which the Ledbury, 

 snow, John Lorain, master, was carried over the reef by the N."W. current 

 of the Stream, caused by a gale from the N.E. The vessel bilged in 

 shallow water, but an anchor was thrown out, and the next day she was 

 found to have grounded on Elliot Kay, with the anchor among the trees. 

 The water is supposed at times to have risen to the height of 30 feet, and 

 to have been running against the fury of the winds at the rate of 7 miles 

 an hour. 



(386.) Action of the Moon.— ^Besides the efl'ect which different winds 

 have upon the Stream, it is subject to another power which also directs it 

 toward or from the coast ; and that is, the moon, which, according to her 

 position, has different effects upon it, not, however, in equal power with 

 those of the wind ; but tbe disposition of the Stream is increased to its 

 extreme, if the effect of both the wind and the moon are combined. For 

 at this time, the ocean rising highest, this regulates the flood and ebb 



