THE 
PHYSICAL GEOGRAPHY OF THE SEA. 
CHAPTER I. 
THE GULP STREAM. 
The Gulf Stream, ^ 1.— 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 with 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 w^ater of the 
sea ; so sharp is the line, and such the want of affinity between 
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 
