§ 99-102. THE GULF STREAM. 3| 



99. The water, hot and cold, as it is let into the tub for a warm 

 luustrations. bath, generally arranges itself in layers or sections, 



according to temperature; it requires violent stirring to break 

 them up, mix, and bring the whole to an even temperature. The 

 jet of air from the blow-pipe, or of gas from the burner, pre- 

 sents the phenomenon still more familiarly; here we have, as 

 with the Gulf Stream, the dividing line between fluids in motion 

 and fluids at rest finely presented. There is a like reluctance for 

 mixing between streams of clear and muddy water. This is very 

 marked between the red waters of the Missouri and the inky 

 waters of the upper Mississippi ; here the waters of each may be 

 distinguished for the distance of several miles after these two 

 rivers come together. It requires force to inject, as it were, the 

 particles of one of these waters among those of the other, for 

 mere vis ine,rtia tends to maintain in their statu quo fluids that 

 have already arranged themselves in layers, streaks, or aggrega- 

 tions. 



100. In the ocean we have the continual heavins- of the sea and 



o 



iiovr the water of ^gitatiou of the wavcs to overcome this vis inertia^ 

 fere from the liai ^^^l the marvcl is, that they in their violence do 

 ^**^^'^- not, by mingling the Gulf and littoral waters to- 



gether (§ 70), sooner break up and obliterate all marks of a di- 

 vision between them. But the waters of the Gulf Stream differ 

 from the in-shore waters not only in color, transparency, and tem- 

 perature, but in specific gravity, in saltness (§ 102), and in other 

 properties, I conjecture, also^ Therefore they may have a peculiar 

 viscosity, or molecular arrangement of their own, which further 

 tends to prevent mixture, and so preserve their line of demarka- 

 tion- 



101. Observations made for the purpose in the navy show that 

 Action on copper, ships cruisiug in the West Indies suffer in their 



copper sheathing more than they do in any other seas. This 

 would indicate that the waters of the Caribbean Sea and Gulf 

 of Mexico, from which the Gulf Stream is fed, have some peculiar 

 property or other which makes them so destructive upon the cop- 

 per of cruisers. 



102. The story told by the copper and the blue color (§71) indi- 

 saitnesa of the Gulf catcs a higher poiut of saturation with salts than sea 

 stream. watcr generally has ; and the salometer confirms it. 



