1872.] 



' Shearwater 3 Scientific Researches. 



627 



before reaching the Meridian of 30° W., the Gulf-stream, to use the language 

 of Dr. Hayes, " has lost every distinctive character as a current : first, in 

 " rate of flow, which has become that of the general easterly * set ' of the 

 " Atlantic ; second, in temperature, which has become that of the general 

 " temperature of the air ; third, in colour of water, which has lost the blue 

 " that it had whene merging from the Gulf of Mexico ; in every thing, in 

 " fact, which goes to make up what we designate as an ' ocean-current. ' " 

 This general Easterly " set," according to the Admiralty Chart, prevails 

 over the whole area of the Atlantic between the parallels of 43° (Cape 

 Finisterre) and 55° (Belfast), taking a more northerly direction in still 

 higher latitudes. Its usual rate appears to be from 6 to 24 miles per day, 

 varying with the degree in which the westerly " Anti-trades " predomi- 

 nate in force and duration over other winds. That it is essentially inde- 

 pendent of the Gulf-stream, seems to be distinctly indicated by the fact 

 that it commences from the very edge of the Arctic current, on the Eastern 

 side of the broad band which it covers, as far as 10° to the north of the 

 Gulf-stream, running parallel to its course. Although mainly due to the 

 dominant influence of the "Anti-trades," yet it may be partly accounted 

 for in another way ; for if, as I have already argued (§ 13), the great body 

 of swS-surface-water occupying this band has been drawn into it from a 

 lower latitude, this water will tend (like that of the Gulf-stream itself, 

 § 144) to move from West to East, in consequence of the excess of easterly 

 momentum it has brought with it. 



149. Now in the midst of this general Easterly " set," the only indica- 

 tion of any continued movement of the Gulf-stream in its original direction 

 is the variable Current known as " Bunnell's ;" which, flowing Eastwards into 

 the southern part of the Bay of Biscay, is then deflected in a north-westerly 

 direction by the turn of its coast-line, so as to cross the Channel towards 

 the Scilly Islands, and thence passes to the S.W. coast of Ireland. Though 

 this is usually described as "a branch of the Gulf-stream," I look upon it 

 as the principal continuation of that portion of it which does not turn 

 southwards round the Azores ; there being no apparent reason for a North- 

 ward deflection of its flow, and no indication of such deflection other than 

 that which surface-drift is quite sufficient to account for. For this takes 

 up and carries onwards any floating bodies which the Gulf-stream has 

 transported into the Mid-Atlantic ; and the fact that these are carried 

 rather to the West of Ireland, the Hebrides, the Orkney, Shetland, and 

 Faroe islands, and even to Spitzbergen, than in the direct Easterly course 

 towards the Bay of Biscay which the Gulf-stream has when it ceases to be 

 recognizable as a distinct Current, seems a clear indication that their trans- 

 port over the latter part of their course is essentially due, as was long ago 

 suggested by General Sabine (§ 88), to the predominance of South-westerly 

 winds over this portion of the area of the Atlantic. — It is well remarked by 

 Dr. Hayes, that just as a ball fired from a cannon stationed on the top of 

 a hill loses its velocity with every second of its progress, and falls to the 



