THE OCEAN. 



Gale in the Pacific. 



which lasted with unabated violence for two days. During the greater part of the gale 

 the wind was fair, but blowing so hard, and with so mountainous a sea, that we could 

 make no use of it, nor show even the smallest stitch of sail, without its being instantly 

 blown to rags." 



The temperature of the ocean has occupied the attention of many physical inquirers. 

 Water, being a slow conductor of heat, its temperature is less affected by change of seasons, 

 and is therefore more stable than that of the atmosphere. In the ocean, the influence of 

 seasonal vicissitudes is imperceptible at the depth of about 300 feet ; and at a depth which 

 varies with the latitude, the same temperature appears to be invariably maintained that 

 of 39^ marking the limit of the influence of solar heat. This interesting result was 

 ascertained with reference to the southern seas during the Antarctic Expedition, under Sir 

 James C. Ross. In equatorial latitudes, the line of unvarying temperature is reached at 

 the depth of 1200 fathoms. From thence, it is found at a lesser depth, till it comes to 

 the surface in latitude 56^ S. ; and here the water has the temperature of 39^ at all 

 depths. From the latitude named, to near 70, the line descends to 750 fathoms, 

 beneath which, to the greatest depths, the temperature of 39^ obtains, while that of the 

 upper stratum is much lower. The thermal condition of the ocean in the northern 

 hemisphere may be assumed to be much the same in closely corresponding latitudes ; and 

 thus there exist, in the upper part of the oceanic expanse, two great thermic basins, one 

 warmer, and the other colder, than the temperature named. 



The diagram, founded upon Ross's data, and applied to the northern hemisphere, exhibits 

 the ocean from pole to pole, and approximately the two basins respectively warmer and 

 colder than the stratum of unvarying temperature. 



