Page:Physical Geography of the Sea and its Meteorology.djvu/141

 Rh (4.) Parallel for parallel, the southern hemisphere from the equator to 40° or 45° S., is the cooler. This fact is consistent with the supposition that the heat that is rendered latent and abstracted from that hemisphere by its vapours is set free by their condensation in this. Upon no other hypothesis than by these supposed crossings can this fact he reconciled, for the amount of heat annually received from the sun by the two hemispheres is, as astronomers have shown, precisely the same.

(5.) Well-conducted observations made with the hydrometer (§ 285) for every parallel of latitude in the Atlantic Ocean from 40° S. to 40° N., show that, parallel for parallel, and notwithstanding the difference of temperature, the specific gravity of sea-water is greater in the southern than it is in the northern hemisphere. This difference as to the average condition of the