18 THE BOTTOM OF TITE SEA. 



tions have been made by tlie scientific voyages of 

 observation sent out at the expense of States ; but 

 except these we know of none that are available. 



T!ie southern part of the Athmtic Ocean is equally 

 a blank ; and to make a sum of the whole matter, 

 the greater part of the wcrld beneath the sea is in- 

 differently known. If we add to this fact, that the 

 greater part of continents is desert or savage, traversed 

 occasionally by a few hardy adventurers, we shall 

 begin to see how vast are the lacunae still remaining 

 in our study of the globe, and what an ample harvest 

 of discovery may yet be reaped by the conscientious 

 observers of nature. 



3. Analogy between the Configuration of Continents, and that of 

 the Bottom of the Sea — Equatorial Section of the Earth. 



Although the scientific results which we have al- 

 ready mentioned are incomplete, they are sufficient to 

 prove that the greatest depth of the sea does not ex- 

 ceed about five miles ; thus, that it is about equal to 

 the height of the loftiest mountains. This depth 

 has been plummed in all the great oceans, and occa- 

 sionally deeper soundings have been reported. The 

 results, however, in the latter case have been obtained 

 under circumstances which do not command our 

 confidence. Such are the cases in which it would be 

 eminently satisfactory to employ an instrument to 



