THE SPECIFIC GRAVITY OF THK SEA, ETC. 233 



one hemisphere and the arrangement of the water in the other ; 

 between the rains of the northern and the winds of the southern 

 hemisphere ; between the vapour in the air and the salts of the 

 sea ; and between climates on opposite sides of the equator. And 

 all this is suggested by merely floating a glass bubble in sea 

 water during a voyage to the Pacific ! Thus even the little 

 hydrometer, in its mute way, points the Christian philosopher to 

 the evidences of design in creation. That the arrangements 

 suggested above are adapted to each other, this insti-ument affords 

 us evidence as clear as that which the telescope and the micro- 

 scope bear in proof that the eye, in its structure, was adapted to 

 the light of heaven. The universe is the expression of one 

 thought, and that it is so every new fact developed in the pro- 

 gress of our researches is glorious proof. 



457. Barometer indications of an open sea. — ^In the course of our 

 investigations into the physics of the sea, 100,000 observations 

 of the barometer, and more than a million on the direction of the 

 winds have been discussed. They indicate an open water in the 

 Arctic Ocean. They show that about the poles there is a high 

 degree of aerial rarefaction — higher, indeed, than there is about 

 the equator; for the barometer not only stands lower in this 

 place of polar calms than it does in the equatorial calm belt, but 

 the inrushing air comes from a greater distance to the cold than 

 to the warm calms.* 



458. Polar rarefaction. — The question may be asked, Whence 

 comes the heat that expands and rarefies the atmosphere in these 

 polar places ? The answer is, it comes from the condensation of 

 vapour. The south pole is surrounded by water, the north pole 

 by land. But the unexplored regions within the arctic basin are 

 (§ 429) for the most part probably sea, within the antarctic, land. 

 The rarefaction produced in the latter by the latent 'heat of 

 vapour is such that the mean height of the barometer there is 

 about 28 inches, while that in the arctic calm place is such as to 

 reduce the barometer there to a mean not far from 29.5 inches. 

 In the equatorial culm its mean height is about 29.9 inches. The 

 hypothesis of an open sea in the Arctic Ocean becomes necessary 

 to supply a source for this vapour ; for the winds, entering the 

 Arctic Ocean as they do after passing over land and mountain 

 heights of America, Europe, and Asia, must be robbed of much 

 of their moisture ere they reach that ocean ; it will require an 



* Plate IV., Nautical Monograph Na 1. 



