3l8 Tlie American Geologist. May, i89>4 
Transporthig Power. — Additional evidence against the 
existence of such a torrent as has been described is found in 
the size . of the material of which the sand-plains are com- 
posed. The predominating material is sand, and could only 
have been deposited in a current moving at a rate of less than 
one foot per second. Further back, and nearer the point of 
emergence of the glacial stream from the ice, the material 
becomes coarser^ the sand giving place to fine gravel and 
indicating, perhaps, a current of two feet per second. Still 
nearer the head of the plain gravel is found indicating currents 
of three, four or even five feet per second, while in the esker 
left by the stream, as for example, the Barrington stream, 
stones up to six inches in diameter, and indicating a current 
of a little less than 6.4 feet per second, were observed. 
The evidence of the material thus fixes a maximum to the 
actual velocities of the waters in which the sand plains were 
laid down. With this velocity the velocities necessitated by 
the assumptions of glacial Hoods as a cause for the hight of 
the waters in Narragansett bay in Champlain times, forms a 
striking contrast. As we have seen, the highest velocity in- 
dicated by the material of the salnd plains is about six feet 
per second, a velocity which would be capable of moving 
almost exactly 17 pounds. The actual velocity of the postu- 
lated flood would, in the region of the sand-plains be 11. 18 
feet per second, and would be sufficient to roll along boulders 
505 pounds in weight, or thirty times the size of the largest 
material of the sand-plains. In the Eastern passage the cur- 
rent would have been sufficient to have transported a boulder 
over two tons in weight, or about 240 times the size of the 
material at the head of the plains. 
Problem of Ice Barriers. — An increase in the hight of the 
waters by simple flood demands torrents far beyond the range 
of possibility. Ice barriers, in the sense ordinarily used, are 
admittedly out of the question. Only barriers formed by the 
temporary gorging action of floating ice need, therefore, be 
considered. 
The ice, if in motion, would undoubtedly furnish an abund- 
ance of icebergs wherever it came in contact with the water. 
It is, however, a well known fact that such was not the case 
at the time of the deposition of the sand-plains, distortion, 
