The Isthmus of Tehuantepec. 157 



they built two small vessels, and pursued their fruitless search 

 toward the isthmus of Dariep. However disappointed 

 Cortez may have been at not finding the promised gold on 

 the isthmus of Tehuantepec, he still had faith, for other 

 reasons, in that part of his conquered provinces, for, on 

 being allowed to choose a portion for himself, and his 

 heirs, he took the central part of the isthmus, and there, 

 Spaniards, claiming descent from him, exist to this day. 



In later days, several expeditions have been sent from 

 France, and the United States, to survey this part of the 

 country, so that, while the greater portion of Mexico is 

 almost unknown, this has hardly a stream, large enough 

 for a canoe, nor a hill over an hundred feet high, which 

 has not been accurately measured, and mapped. 



The object of this essay is to lay before the society a 

 description of the isthmus and its peculiarities, in the hope 

 that, as the rival advantages of the route for a canal, there, 

 and at Darien, and Nicaragua, are now before the public, 

 such a description may prove interesting. 



The general direction of the coast at the mouth of the 

 river Coatzucolcas, which empties into the sea in latitude 

 18° 30', and longitude 94° 32', is east and west. The 

 shortest distance across the isthmus, on a north and south 

 line, or nearly north and south, is one hundred and forty- 

 five miles. 



There are three topographical divisions, which may be 

 called Atlantic Plains, Pacific Plains and Table Lands. 



The Atlantic Plains are low and flat, forty or fifty miles 

 wide, extending from the sea, to the head of the navigable 

 rivers at the base of the Table Lands. They are almost 

 level, having only rise enough toward the mountains to 

 give a current of four or five miles an hour. The soil is 

 a rich alluvial deposit, covered with tropical vegetation. 



The banks of the rivers are of uniform height, about ten 

 feet above the river, in dry weather, and apparently per- 

 manent. 



