a Theory of the Earth. 39 



4. Currents at the furface or at different depths; their 

 direction, velocity and limits; their relation to rivers, the 

 v.inds, and form of the eoafts ; the matters which they ac- 

 cumulate, and the places where they depofit them. 



5. Subterranean mountains and valleys; their relation 

 with iflands, and even with the terreftrial mountains and 

 valleys. 



6. The nature of the mud, fand and rocks, of which the 

 bed of every fea is compofed. 



7. An analyfis of the water of the different feas; and, at 

 leaft, their faltnefs at different depths and in different climates. 



8. Their temperature at different depths and in different 

 climates. 



9. The fifh and teftaceous animals peculiar to different 

 feas, depths and climates, which may ferve to characterise 

 them. 



10. In what the prefent feas differ, in a phyfical and 

 chemical view, from the great ocean, which, according to 

 fome fyltems, is fuppofed to have covered the whole furface 

 of our globe ? 



1 1 . Can we believe that there are ftill formed ftoney ftxata 

 at the bottom of the feas, and that their waters have confe- 

 quently that diffolving power which is fuppofed to have be- 

 longed to the ancient ocean ? 



chap. v. 



Obfervat'wns to he made on the Borders of the Sea. 



1. If the fea coaft is fleep ; if it forms fteep hills, to ob- 

 fcrve their height, their nature, and the ftrata of which they 

 oonfift *. 



2. To feek on thefe hilh traces of the effects or abode of 

 the waters at different heights above the prefent level, and 

 ai different depths below, fuch as furrows, caverns, fliells, 



'* 1. A. To note down every thing that relates to the deftruclion, mora 

 cr lef; rapid, of tlufe hills, and the banks and accumulations formed chiefly 

 At the mouths of river j. C. 



P 4 fboladci ; 



