16 THE BOTTOM OF THE SEA 



The terrestrial shell is known to be irregularly 

 broken, and its fragments, so to speak, piled on one 

 another in gigantic masses of picturesque confusion — 

 here heaved up into the air, there sunk from depth 

 to depth, with the waters of ocean gathered in their 

 deepest gulfs. Plainly, if we add to the measurement 

 of these depths beneath the sea that of the heights 

 above, we shall obtain some useful data, and be 

 enabled to form an approximate estimate of the 

 stupendous forces in the interior of the globe 

 which have produced such irregularities on its 

 surface. 



Before Maury made his appeal to the marine of 

 all nations, something was known of the sea-bottom 

 in the vicinity of coasts, and in the most frequented 

 tracts ; but very little was apprehended of what lay 

 under blue water. He called upon his brother sailors 

 to commence a systematic observation of the winds 

 and of meteoric phenomena, to note the marine cur- 

 rents, and to sound the sea as they traversed it, if 

 possible, every hundre 1 leagues. His call was heard, 

 and heartily responded to. In a few years the North 

 Atlantic, ploughed by the ships of all nations, had 

 been sounded in so many points, that Maury was able, 

 by combining the results obtained, to trace the con- 

 fioiiration of the bottom of that ocean, and construct 

 a chart analogous to a geographical tracing designe;! 



