AND ITS DELTA. 167 



which caused great astonishment, because from the commence- 

 ment of their settlements, which exceeded 20 years, they had 

 rarely ever seen the Mississippi surmount the level of its banks, 

 and that an embankment, called by the french name of levee, 

 was required only in very few places. Since that period, from 

 year to year, the river has continued to rise higher and higher, 

 which has obliged the inhabitants of Lower Louisiana to pro- 

 long and reinforce their levees; in so much that embankments 

 of 5 or 6 feet perpendicular are now required, where as many 

 inches were formerly sufficient. This increasing ascent of the 

 inundation may be naturally accounted for by the gradual ex- 

 tension of the levees on both sides of the river, which became 

 each succeeding year more necessary for the defence of the new 

 settlements against the encroachments of this great river. 

 Those establishments are now extended on either bank to the 

 distance of 60 leagues above the capital ; it is not therefore won- 

 derful that high banks in the lower parts of Louisiana should 

 be required to receive and confine a body of water which for- 

 merly escaped over a great extent, now occupied by the em- 

 bankments. In spite of this mode of reasoning, which appears 

 to be sufficiently satisfactory, the Mississippi has ceased to rise to 

 its usual height for these* three years past; the defect at Natchez 

 has not been less than from 8 to 12 feet, and proportionably in 

 the lower country. Many are the conjectures which have 

 been formed to account for this unexpected great change. 

 Some of the old inhabitants say that the Mississippi has returned 

 to its ancient level, while others pretend (ludicrously enough) 

 that the Missouri has found a new passage into the western Pa- 

 cific Ocean. It does not appear, that we can assign any phy- 

 sical cause why the Mississippi should have certain periods of 

 years in respect to its inundations; nor have observations been 

 made for a sufficient length of time to establish the fact. The 

 late period of great inundations, which have fallen chiefly 

 under my observations, has been about 27 years, not much 

 short of a cycle of the sun; but whether the inundations of 

 this great river are subject to the influence of any regular 

 cause, must be left to die investigation of future philosophers, 

 profoundly skilled in the laws of meteorology. 



* This account was commenced in 1800. 



