58 



bank of Newfoundland. It would be difficultto 

 fix the rapidity of the retrograde current from 

 this bank to the coasts of Africa : estimating the 

 mean velocity of the waters at seven or eight 

 miles in twenty-four hours, we find ten or eleven 

 months for this last distance. Such are the ef- 

 fects of this slow but regular motion, which agi- 

 tates the waters of the ocean. Those of the river 

 of the Amazons take nearly forty-five days to 

 flow from Tomependa to Grand Para. 



A short time before my arrival at Teneriffj the 

 sea had left in the road of St. Croix a trunk of a 

 cedrela odorata covered with the bark. This 

 American tree vegetates exclusively under the 

 tropics, or in the neighbouring regions. It had no 

 doubt been torn up on the coast of the continent, 

 or of that of Honduras. The nature of the wood, 

 and the lichens which covered it's bark, were 

 evident proofs, that this trunk did not belong to 

 these submarine forests, which ancient revolu- 

 tions of the globe have deposited in lands trans- 

 ported from the polar regions. If the cedrela, 

 instead of having been thrown on the strand of 

 TenerifF, had been carried fart her south, it would 

 probably have made the whole tour of the At- 

 lantic, and returned to it's native soil with the 

 general current of the tropics. This conjecture 

 is supported by a fact of more ancient date, re- 

 corded in the general history of the Canaries by 

 the Abbe Viera. In 1770, a small vessel laden 



