1872.] 



' Shearwater 9 Scientific Researches. 



625 



Gulf-stream proper ; but to the east of this, beyond another cold band of 

 37 miles breadth, there is still another warm band 75 miles broad. — Off 

 Sandy Hook, where the Stream makes its great bend to the East, and the 

 ft cold wall "is at a distance of 240 miles from the shore, the " Gulf- 

 stream proper" has only increased in breadth from 117 miles to 127 ; but 

 the breadth of the second cold band has now increased from 37 miles to 

 60, whilst the breadth of the third warm band has diminished from 75 miles 

 to 50 ; the outer portion of the Stream showing an obvious tendency to 

 lose itself in the general mass of Oceanic water. — The total breadth of the 

 Gulf-stream is stated by the American Surveyors to be 350 miles off Cape 

 Hatteras, and 410 miles off Nantucket; but as the outer boundary is not 

 well denned, these estimates are only approximative. 



146. The difference in the rate of movement of these bands is probably 

 one source of the discrepancy in the statements given by different autho- 

 rities as to the rate of the flow of the Gulf-stream as a whole. It is com- 

 monly said to pass Nantucket at the rate of about one mile an hour ; and 

 an observation cited in Blunt's ' Coast Pilot' would give about 0*7 mile 

 per hour as its rate between W. Long. 57° and 55§°, between the 41st and 

 42nd parallels of Latitude. Many degrees to the east of this, however, a 

 very rapid current — running at the rate of even four miles an hour — has 

 been occasionally observed ; and this is probably due, like that sometimes 

 seen off Cape Hatteras, to the lateral pressure exerted by the Arctic cur- 

 rent, which comes down in full force over the Banks of Newfoundland, 

 sometimes extending far to the southward, directly into the course of the 

 Gulf-stream. It is during the early months of the year that, under the 

 influence of the N. and N.W. winds which then prevail along the coast of 

 Labrador, the Arctic current — bringing with it immense fields of polar ice 

 — is at its strongest ; and the Admiralty Chart shows the southward ex- 

 tension of this field-ice, between March and July, reaching even to the 42nd 

 parallel between the meridians of 55° and 45° W. Long. ; while between 

 April and June, icebergs range as far South as 39° between the meridians 

 of 50° and 40°. This enormous body of Polar ice-laden water must have 

 a powerful influence both on the movement and on the temperature of the 

 Stream against which it impinges, more especially since the deep-floating 

 icebergs will bring this influence to bear directly on its deeper strata ; 

 and it is considered by Mr. Findlay that " by the time the Gulf-stream 

 " has reached this limit, its original character is so thinned out and ex- 

 " panded, and its specific character is so destroyed from this cause, and 

 " from the neutralizing effects of the Labrador currents, that it can no 

 " longer be recognized beyond this cold-water gulf, which cuts off, as it 

 " were, its further progress, and which, it is manifest, it can neither bridge 

 "over nor pass under." (Proc. Roy. Geogr. Soc, Feb. 8, 1869, p. 107.) 

 ■ — That the Stream has here for the most part thinned-out to a compara- 

 tively shallow stratum running over much colder water, is indicated by the 

 observations of Capt. Chimmo (Op. cit. p. 92 et seq.), which were made 



