PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. Gil 



the Gulf stream, whose waters are a thousand times the volume of 

 the Mississippi, and not less rapid in movements or less extended 

 in length of travel. As before mentioned, the Gulf stream has a 

 fall of about 250 feet ; this is not so great a fall as that of the Mis- 

 sissippi, but that stream flows through a very crooked, rough and 

 comparatively narrow bed, making the friction much greater, 

 which disposes of the excess of propelling power in that case. 

 The actual propelling power of the Gulf stream is susceptible of 

 being calculated with considerable accuracy, when we know the 

 temperature of its water and the temperature of the ocean upon 

 each side of it. The polar diameter of the earth is 26 miles less 

 than its equatorial diameter, and the surface of the ocean at the 

 equator stands about 13 miles higher than at the poles. This pro- 

 tuberance is caused, of course, by the centrifugal motion of the 

 earth. 'No^v, the important fact in this proposition is this, v^'hen 

 the waters of the ocean are cooled and become heavier, then the 

 centrifugal protuberance of the ocean becomes greater, or is 

 increased ; and if the whole ocean were heated, and of a less spe- 

 cific gravity, then this protuberance becomes less. If by any 

 means the gravity of the waters of the ocean could be entirely 

 annihilated, then the equatorial protuberance of the ocean and its 

 gravity would both run out to nothing, and disappear at precisely 

 the same time. This, at first sight, may seem rather problemati- 

 cal, but it is, nevertheless, a. fact. It is true that when the equa- 

 torial protuberance is inci-eased by cold and heavy water, the 

 water has greater gravity to contend with at the same time that its 

 centrifugal power is increased, but as the water rests upon the floor 

 of the ocean, its increased gravity can only act on an inclined 

 plane — which is, from the equator to the pole, 6,000 miles in 

 length — and this increase of gravity has less than one-fifth of one 

 degree of direct action ; while on the other hand, the increase of 

 centrifugal force acts more directly, or at a resultant angle of 45 

 degs., and consequently gains very rapidly in power over 'such 

 opposing gravitating force, when the weight of water is increased. 

 The result is, that the protuberance of the ocean is increased with 

 its specific gravity. The comparative power of the two forces is 

 this : If a culnc rod of water has its specific gravity increased 

 461 pounds, then this increased gravity can oppose an increase of 

 protuberance only to the extent of one pound of direct force ; 

 while the centrifugal power or force is directly incrctisod 230 

 pounds, leainng a clear gain of 229 pounds of centrifugal force 



