187 



Off cape Courtin, latitude 33 8' north, at two leagues 

 or more, there is, at forty and fifty fathoms of water, a 

 bottom of mud. Vol. II. page 39. 



Off Mogador, at a league from land, we have twenty 

 fathoms of water ; at two leagues, bottom of rock ; and 

 at three and four leagues, and more, and at thirty-five 

 and forty fathoms of water, the bottom is mud, with 

 sand.* Vol. II. page 40. 



I have been thus particular to give the different 

 soundings, in order to show, that almost uniformly, as 

 we recede from the coast and come into deep water, 

 the bottom of the ocean is mud ; differing however in 

 its characters, in different places, and seldom liable to 

 change ; hence the importance of a knowledge of the 

 various soundings to navigators, who well know, if 

 they are skilful, when they approach a particular part 

 of a coast or country, by this highly important crite- 

 rion. 



On the coast of West Florida and of Pensacola bay, 

 in 60 fathoms water, we have a sandy bottom. At 

 about five leagues from Mobile bay in 120 fathoms wa- 

 ter, we have a bottom of mud and sand.f 



The soundings at a great distance to the eastward of 

 George's banks, on the coast of America, and what is, 

 I believe, called Boston channel, and at the depth of 

 sixty or seventy fathoms, discover a muddy bottom, 

 (or what is commonly called by mariners, green ooze,) 



* See Valentia's Travels, vol. II, page 261, &c, on the Sound- 

 ings of the Red Sea. 



t See Mr. Darby's excellent map. 



