174 On the Gulf Stream and Currents of the Sea. 



exerts an obvious and sensible force to put itself in motion. May- 

 there not exist between warm and cold sea water a tendency- 

 somewhat similar to that between oil and water ? Seeing how 

 great is the resistance encountered by the Gulf Stream in its east- 

 ward motion, and how insufficient is any head of water in the 

 Gulf to give it its northward tendency, may there not exist be- 

 tween the tepid waters of the stream and their fluid banks always 

 heaving and moving to the swell of the sea, a sort of peristaltic 

 force, which, with other agents, assists to keep up and preserve 

 this wonderful system of ocean circulation? We know that 

 imdulatory motion varies with temperature in certain other sub- 

 stances, and why should it not vary in water also ? 



Sir Isaac Newton demonstrated the velocity of waves to be 

 in the sub-duplicate ratio of their breadths. Therefore, if two 

 vessels, in a calm, one in and the other on the outside of the Gulf 

 Stream, would each count the waves that pass, or the times that 

 the vessel rolls from the one side to the other in a given time, we 

 should have an argument for determining whether the oscillation 

 of a wave in the Gulf Stream be shorter or longer, whether the 

 rise and fall be greater or less, or whether there be any difference 

 whatever between the warm wave and the cold one from which 

 it is generated. That the waters of the Gulf Stream are more 

 troubled than those of the Atlantic is well known by the ugly seas 

 which are so much dreaded there by navigators. 



But we want facts, and not theory. We have not enough of 

 the former to build up any theory at all ; nor should I undertake 

 the structure if we had. In planning a system of observations in 

 this magnificent field, instruction should cover the whole ground, 

 and the attention of observers should be directed to every point 

 from which it is possible or probable that light may come. There- 

 fore, in throwing out these suggestions, sailor-like, I have but cast 

 over my bottles ; perhaps they may be picked up at some distant 

 day — perhaps they may never be heard of again. 



In its course to the north, the Gulf Stream naturally tends 

 more and more to the eastward, until it arrives off the Banks 

 of Newfoundland, where its course is said to become due east. 

 These banks, it has been thought, deflect it from its pro- 

 per course, and cause it to take this turn. Examination will 

 prove, I think, that they are in part the effect, certainly not the 

 cause. It is here that the frigid current from the north, already 



