proceedings of the polytechnic association. 503 



Earthquake of 1811 — Sandplows — Fissures — Production of 



Lakes. 



Truy, Obion county, Tennessee, is situated witliin tlie vanj^e of the great 

 cartlujuuke of 1811, which destroyed New Madrid, on the Mississippi rivel". 

 There arc two lakes in the neiffhborhood of Trov, which were formed durinjr 

 this earthquake. One of these lakes, visited during my journeyings, is 

 called Reel-foot Lake, and is from one to four miles wide, and forty miles 

 long. It runs parallel with the Mississippi, but owing to the serpentine 

 course of that stream, it variea in distance from it at some points one mile, 

 at others eight- Reel-foot river, which supplies this lake, had its outlet 

 formerly into the Mississippi, forty or fifty miles above its present mouth, 

 which is into the Obion riv(!r. 



The general opinion has been that this lake, as well as the less extensive 

 one formed by the Obion river, were both produced by the sinking of the 

 earth; but an intelligent gentleman of that vicinity atsured me that this 

 theory of their origin was erroneous. 



The first question, of course, was wliether these lakes were formed by the 

 earthquake. An affirmative answer was soon given. Military land war- 

 rants had been laid upon the lands now covered by the lakes, some time 

 previous to their immersion, and the surveys made and recorded; and bills 

 for the relief of those who had lost their lands by the earthquake, allowing 

 them to lift their warrants and locate elsewhere, had passed the National 

 Legislature. Before the passage of tliis relief law, one man had sold his 

 tract as first rate land; but tiie purchaser finding himself in possession of 

 only a ''water right," lesorted to lynch law and shot down the seller. For- 

 tunately he recovered from his wounds, but with the loss of his left eye— a 

 misfortune that turned to his advantage afterwards, as surveyor, enabling 

 him to use his instruments, in sighting, without the trouble of shutting an 

 eye. These facts are conclusive as to the earth(^uake origin of the lakes. 



Bat other testiraonj^, of more importance to science, and equally conclu- 

 sive, still exists. Trees of the largest class, which grow only upon dry 

 grounds, were yet standing in the lakes at the time of my visit in 18-16, 

 but were all dead. The trunks of tlic cypress trees, wliich grow only in 

 swamps, partially covered by water, were submerged to the height of four- 

 teen or fifteen feet. The walnut, oak and other dry land trees, were but 

 slightly sunk in the water, sometimes only a few inches. There were also 

 points in the lakes where the trees are still growing, the grounds being 

 higher than the surface of the lake, and not covered by water. 



It v,'ould appear from these facts that drj' land has existed on the spot 

 now occupied by the lake, and that the period when the water attained its 

 present elevation is so recent that green trees then submerged, so as to kill 

 them, have not yet had time to rot down; and that the rise of the water 

 must have been at least sixteen feet, because the cypress swamps are, 

 generally, at least two or three feet above the level of the water in the 

 streams, while the cypress trees in the lakes have their trunks covered to 

 the height of fourteen or fifteen feet. 



These lakes, being of recent origin, the question remaining to be an- 

 swered is, how were they produced 



