THE 



PHYSICAL GEOGRAPHY OP THE SEA. 



CHAPTER I. 



THE GULF STREAM. 



The Gulf Stream, <J l.~Its Color, 2.— Its Cause, 3-7.— Dr. Franklin's Theory, 8.— 

 The Sargasso Sea, 13. — The Trade-wind Agency refuted, 14. — Galvanic Properties 

 of Gulf Stream Waters, 26. — Initial Velocity, 30. — Agents that make Water in one 

 part of the Sea heavier than in another, 31. — Temperature of the Gulf Stream, 37. 

 — It is Roof-shaped, 39. — Why the Drift Matter of the Gulf Stream is sloughed off 

 to the right of its Course, 42. — Course of the Gulf Stream, 47. — Currents run along 

 arcs of Great Circles, 49. — The Course of Currents counter to the Gulf Stream, 52. 

 — The Force derived from Changes of Temperature, 53. — Limits of the Gulf Stream, 

 for March and September, 54. — Streaks of Warm and Cool Water in it, 55. — A 

 Cushion of Cold Water between the Bottom of the Sea and the Waters of the Gulf 

 Stream, 56. — It runs up hill, 57. 



1. There is a river in the ocean. In the severest droughts it 

 never fails, and in the mightiest floods it never overflows. Its 

 banks and its bottom are of cold water, while its current is of 

 warm. The Gulf of Mexico is its fountain, and its mouth is in 

 the Arctic Seas. It is the Gulf Stream. There is in the world 

 no other such majestic flow of waters. Its current is more rapid 

 than the Mississippi or the Amazon. 



2. Its waters, as far out from the Gulf as the Carolina coasts, 

 are of an indigo blue. They are so distinctly marked, that their 

 line of junction w^ith the common sea- water may be traced by the 

 eye. Often one half of the vessel may be perceived floating in 

 Gulf Stream water, while the other half is in common water of the 

 sea ; so sharp is the line, and such the want of affinity betw^een 

 those waters, and the reluctance, on the part of those of the Gulf 

 Stream to mingle with the common w^ater of the sea. 



3. What is the cause of the Gulf Stream has always puzzled 



