I9II.] STEVENSON— FORMATION OF COAL BEDS. 549 



river had still its virgin forest, there being only a few, insignificant 

 settlements west from the Alleghany mountains. By 1816, the head 

 of the raft was within 2"] miles of the Mississippi. Darby examined 

 it in that year and reported that it was 20 miles long, 220 yards wide 

 and perhaps 8 feet deep. As it was not continuous, but showed 

 many open spaces, he was convinced that a length of 10 miles would 

 be nearer the truth, thus giving about 4,000,000 cubic yards of loose 

 material as the total accumulation during almost 40 years, practically 

 the total supply of floated timber from the area of more than 800,000 

 square miles. He says that " the tales which have been related 

 respecting this phenomenon, its having timber of large size and in 

 many places being compact enough for horses to cross, are entirely 

 void of truth. The raft, from frequent change of position, renders 

 the growth of large timber impossible. Some small willows and 

 other aquatic bushes are frequently seen among the trees but are too 

 often destroyed by the shifting of the mass to attain any consider- 

 able size." The channel was opened by the state authorities in 1840 

 and the raft disappeared. 



Details respecting variation of position and duration of material 

 were not given by those who described the Atchafalaya raft. But 

 no such lack of information exists respecting the more celebrated 

 raft of the Red river in Louisiana. That stream, formed by tribu- 

 taries rising in the higher lands of Texas and Oklahoma, flows for 

 a long distance through a region of yielding materials, which, in 

 many places, is densely forested. According to Veatch,^'^ this raft 

 began to form in the fifteenth century and by the beginning of the 

 sixteenth, its head was near the present town of Alexandria, some- 

 what more than 60 miles from the Mississippi river. It consisted 

 of a series of complex logjams, each filling the channel. These 

 ponded the river, which found a new outlet above the raft, so that 

 this, by additions, gradually moved stream, becoming a great irreg- 

 ular accumulation of logjams and open water about 160 miles long. 



^ A. C. Veatch, " Geology and Underground Water Resources of Nortfi- 

 ern Louisiana and Southern Arkansas," U. S. G. S. Professional Paper, 46, 

 1906, p. 60. 



147 



