246 OUR HERITAGE THE SEA 



principal among which was, that below a certain depth, 

 say, a thousand feet, life ceased owing to the enormous 

 pressure of the superincumbent weight of water and 

 the absence of air, to name only two reasons which 

 used to be advanced. They have discovered, also, the 

 extreme mobility of the ocean ; in the language of the 

 late hydrographer, Sir W. Wharton, " not one drop of 

 all that vast mass of water is ever for a moment at 

 rest," that is, in the popular sense of motion, and 

 taking no account of the high scientific fact, recently 

 discovered, of the incessant activity of the electrons of 

 which all matter is composed. They have learned a 

 great deal of the contour of the sea- bed, and plumbed 

 its greatest depths in the South Pacific, or at least 

 approximately so to a few yards, an awful abyss just 

 north of New Zealand, with a profundity of six miles. 

 The only other portions of the ocean bed, which nearly 

 approach this stupendous depth, are all fairly close to 

 land : as the deep near Hayti, in the West Indies, 

 28,000 feet ; the trough off the Japanese coast, of about 

 the same depth; and a hole, between the Marianne 

 and Caroline islands, in the North-Western Pacific, of 

 over 27,000 feet. 



Now harking back to the Atlantic again, the 

 explorers have by diligent survey discovered, in the 

 midst of the southern half of that vast and almost 

 landless expanse of water, what they call a ridge, or, 

 rather, a submerged continent, larger than the whole 

 of Scandinavia, which rises from adjacent depths of 

 from fifteen to eighteen thousand feet, to a mean height 

 of about seven thousand feet, leaving its top still some 

 ten thousand feet below the sea surface except at its 

 extremities, where the lonely peaks of Ascension, St. 



