368 Notice of Dr. Beck’s Gazetteer 
well composed and neatly printed, and deserves the patron- 
age of the public. The article, Military Bounty Tract, 
128, and p. 291, contains much very important information 
to the settlers, and those who propose to remove to these 
States. The articles, Pike County, Fort Chartres, Fort 
Dearborn, Monk Mound, and Vandalia, under Illinois ; and 
Fenton, Noyer Creek, St. Louis, Strawberry River, under 
Missouri, are particularly interesting. 
On page sixteen, the length of the Ohio River is stated 
to be one thousand one hundred miles, but the true length 
is, by actual measurement, according to Mr. Darby*, nine 
hundred and forty-eight miles. : 
On p. thirteen, is a correction of a mistake in Mr. School- 
craft’s ** Narrative Journal,” which was repeated in the 
North-American Review, No. 36, respecting the average 
descent of the Mississippi. Mr. S. states the elevation of 
the source of the Mississippi to be one thousand three hun- 
dred and thirty feet about the tide water of the Hudson, 
and the length of the river, three thousand and thirty miles. 
This would give an average descent of nearly forty-four . 
hundredths of a foot, or about five and a quarter inches a 
mile. This is a far less descent than is given either by Mr. 
S. or the Reviewer.. This mistaké was early pointed out 
to the latter, and is too considerable not to merit attention, 
especially as this descent is to account for the rapid current 
‘the Mississippi, whose velocity is generally estimated 
from three to four miles, and by Dr. Beck, from two to 
four milesan hour. The velocity acquired in falling, with- 
out resistance, through five and.a quarter inches, is ‘about 
one foot and a half a second, and would be the velocity of 
the river, if there were no resistance. Allowing this to 
the mean velocity of the river, it would be only one mile 
and one forty-fourth an hour. But considering the resist- 
ance from the bends, sand-banks, counter-currents, &c. it 
cannot be supposed that, with only this descent a mile, the 
velocity can be more than one mile an hour. Mr. Darby 
thinks that the velocity of the current has been much over- 
stated, and that “below the Ohio the entire mass does not 
move as much as one mile an hour,””—that even the veloci- 
ty of the upper current is much less than has been general- 
ly stated. He also estimates the descent of the Mississippi 
*Art. Mississippi River, in the New Edinb. Encyc. 
