CHAP. XXVIII.] BURIED UPRIGHT TREES. 109 



ticed ax-men from Kentucky. I am informed that the superin 

 tendent of the gas-works, Dr. Rogers, who is now absent in Cuba, 

 endeavored to estimate the minimum of time required for the 

 growth of the cypress and other trees, superimposed one upon 

 the other, in an upright position, with their roots as they grew, 

 and had come to the opinion, that eighteen centuries must hava 

 been required for the accumulation. At the time of my visit the 

 section was too obscure to enable me to verify or criticise these 

 conclusions ; but Mr. Bringier, the state surveyor, told me that 

 when the great canal, before alluded to, was dug to the depth of 

 nine feet from Lake Pontchartrain, they had cut through a cy 

 press swamp which had evidently filled up gradually, for there 

 were three tiers of the stumps of trees, some of them very old, 

 ranged one above the other ; and some of the trunks must have 

 rotted away to the level of the ground in the swamp before the 

 tipper ones grew over them. If it be true, as I suspect from 

 these statements, that the stools of trees which grew in fresh 

 water can be traced down to a level below the Gulf of Mexico, 

 we must conclude that the land has sunk down vertically. Per 

 haps some part of this subsidence might arise from the gradual 

 decay or compression of large masses of wood slowly changing 

 into lignite, for carbonated hydrogen is said to be constantly given 

 out from the soil here wherever such masses of vegetable matter 

 are decomposing ; and during the excavation of these works much 

 inflammable gas was observed to escape. That such upright 

 buried trees are not every where to be met with in this part of 

 the delta, I ascertained from Mr. Bringier. At his house, in the 

 suburbs of New Orleans, a well has been sunk to the depth of 

 twenty-seven feet, and the strata passed through consisted of sandy 

 clay, with only here and there some buried timber and roots. 



Walking through one of the streets of New Orleans, near the 

 river, immediately north of the Catholic cathedral, I was surprised 

 to see a fine date-palm, thirty feet high, growing in the open air. 

 (See fig. 8.) 



Mr. Wilde told me, that in 1829, in the island of Anastatio, 

 opposite St. Augustine, in Florida, he saw one still taller, proba 

 bly brought there by the Spaniards, who have introduced them 



