§457, 458. THE SPECIFIC GRAVITY OF THE SEA, ETC. 23i 



The results of the ^lent, tliG marks of design, the evidence of adapt- 

 mariue hydrometer. ^^'^^ between the oibit of the caith and the time 

 from the vernal to the autumnal, and from the autumnal to the 

 vernal equinox ; between the arrangement of the land in one 

 hemisphere and the arrangement of the water in the other ; be- 

 tween the rains of the northern and the winds of the southern 

 hemisphere; between the vapor 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 wa- 

 ter during a voyage in the Pacific ! Thus even the little hydrom- 

 eter, in its mute way, points the Christian philosopher to the evi- 

 dences of design in creation. That the arrangements suggested 

 above are adapted to each other, this instrument affords us evi- 

 dence as clear as that which the telescope and the microscope 

 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 progress of our 

 researches is glorious proof. 



457. In the course of our investigations into the physics of the 

 Barometer indications sca, 100,000 obscrvations of the baromctcr, and 

 of an open sea. morc than a million on the direction of the winds, 

 iiave 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 equa- 

 tor ; 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. The question may be asked, Whence comes the heat that 

 Polar rarefaction, expauds and rarcfics the atmosphere in these polar 



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

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

 But the unexplored regions within the arctic basin are for the 

 most part probably sea, within the antarctic, land. The rarefaction 

 produced in the latter by the latent heat of vapor 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 calm its mean 



* Plate IV., Nautical Monograph No. 1. 



