384 



THE CHEMISTRY OF CREATION. 



It lias been seen that we know but little of 

 the real depth of our " sea of air," for it must 

 be admitted, after all, that our data for the de- 

 termination of this question are not wholly 

 satisfactory, but we know perhaps less of the 

 profundity of the great waters. All that can 

 be learned is the depth down to which our re- 

 searches have extended in the vain search for 

 the bottom. The greatest depth yet obtained 

 was by Sir J. C. Ross, in S. lat. 15 3'. The 



DliJiP SOl'XDINGS. 



weather being calm and the water quite smooth, 

 soundings were tried for with 4,600 fathoms of 



