THE GULF STREAM 



Winds blowing over the surface of the 

 water induce a current in tlie latter due 

 to friction. At first it is only the merest 

 skim that moves, but gradually the mo- 

 tion is communicated from layer to layer 

 until at last, if the wind is long continued 

 as in the trade wind region, the move- 

 ment extends to lower depths, 300 or 400 

 feet, or perhaps more. 



These trade wind currents meet finally, 

 the partial barrier of the islands forming 

 the eastern part of the Caribbean, and a 

 portion of the flow escapes through the 

 passages between them. From here it 

 continues its course across that sea until 

 it reaches the obstruction of the Hon- 

 duras and Yucatan coasts, from which it 

 escapes by the easiest route, which is into 

 the Gulf of Mexico. 



It has been found, however, that the 

 water entering the Caribbean by this 

 means is not more than one-half of the 

 amount which flows through the Straits 

 of Florida from the (xulf of Alexico, and 

 the other half is supplied from a source 

 which does not come under the head of a 

 measurable current. The otJier source is 

 the waz'e caused by the iviud. Every rip- 

 ple carries a certain amount of water in 

 the direction toward which it is flowing, 

 irrespectiA^e of the current caused by its 

 friction, and when the waves become 

 large, tons of water are hurled from the 

 crest into the trough every time the wave 

 breaks. 



In a large area like the Caribbean, 

 having a comparatively constant wind 

 blowing over its whole surface, this ac- 

 tion is practically a simultaneous move- 

 ment of its surface waters to the west- 

 ward and a continual escape of the water 

 heaped 11 ]) at the obstruction oft'ered by 

 the land into the Gulf of Mexico, through 

 the Straits of Florida, and into the At- 

 lantic. 



The Gulf Stream would be little felt 

 on the coast of Europe did it not receive 

 a great addition to its volume of heat 

 when en route. This is by means of a 

 gentle flow from the northeast trade- 

 wind current that passes outside the Car- 

 ibbean Islands and the Bahamas. The 

 surface temperature of this outside cur- 

 rent is about the same in its passage 

 along the West Indian Islands as the 



Gulf Stream in the Straits of Florida, but 

 it is less violent in its movements and 

 there is less intermingling of its upper 

 and lower waters, so that it arrives off 

 Cape Hatteras with a much higher tem- 

 perature than that of the more turbulent 

 Gulf Stream. 



TIIK GULF STREAM HAS NOT CHANGKD ITS 

 COURSE 



Newspaper items are frequent that the 

 Gulf Stream has changed its course, and 

 to its supposed erratic movement is laid 

 the blame of every abnormal season on 

 our Atlantic seaboard. Gulf weed is seen 

 up toward Nantucket, for example, and 

 so the Gulf Stream must have changed 

 its course in that direction. 



The fact is this gulf weed originates 

 in the Sargasso Sea and is transported 

 chiefly by the break of the waves. Some 

 of it enters the Gulf Stream and may be 

 carried by it to beyond Hatteras and fur- 

 ther east, but the fact of meeting it in 

 strange regions is not so much an indica- 

 tion of a current as it is that the wind 

 has caused a sea which has thrown the 

 weed to leeward. Any strong southerly 

 gale to the eastward of Cape Hatteras 

 will strip the little gulf weed remaining 

 in the Gulf Stream at that point and 

 carry it toward the X'antucket shores. 



The same influence of the wind to 

 transport the water without an accom- 

 panying current is seen at Key West. 

 With a southerly wind the clear water of 

 the Gulf Stream is thrown into that har- 

 bor in spite of an ebb tide, and it is often 

 accompanied by fragments of gulf weed, 

 but upon a change of wind from the 

 northward (which is from the Gulf of 

 Mexico ) the harbor waters soon cloud 

 up. 



Quite recently the overwhelming" Ti- 

 tauic disaster, which was due to icebergs 

 on the border of the eastern extension of 

 the Gulf Stream, has led to the theory 

 that the stream was feeble and had not 

 been flowing with its usual strength and 

 so the bergs were farther south than 

 usual. Of course, there are periods of 

 heat and cold — one year may vary no- 

 ticeably from another — and perhaps an 

 abnormal amoiuit of heat transported to 

 the Arctic regions some years ago by the 



