DEPTH OP THE OCEAN. 
9 
dM. Maury has also published many charts, giving tho depths of the 
°cean, the substance of which is given in the accompanying map, which 
represents the configuration of the Atlantic up to tho tenth degree of 
south latitude, not in figures, as in Dr. Maury’s charts, but in tints ; 
diagonal fines from right to left, representing the shores of both hemi- 
spheres, indicate a depth of less than a thousand fathoms ; from left 
1° right, indicate bottom at one thousand to two thousand ; horizontal 
hues, two to three thousand fathoms ; cross fines show an average depth 
°f three to four thousand fathoms ; finally, the perpendicular fines in- 
dicate a depth of four thousand fathoms and upwards. Solid black 
Fig. 2. Chart of tho Atlantic Ocean. 
mdicates continents and islands ; waving lines, surrounding both 
c °ntments at a short distance from the shore, indicate the sands which 
surround the coast fine at a little distance from the shore. 
1 he question is sometimes asked, What useful purpose is served by 
Jj, uil g soundings at great depths ? To this we may quote tho answer 
0 Franklin to a similar question, addressed to aeronauts — “ What 
Puipose is served by the birth of a child ?” Every fact in physics is 
Interesting in itself ; it forms a rallying point, round which, sooner or 
a er ’ others will meet, in order to establish some useful truth ; and the 
