368 Notice of Dr. Beck's Gazetteer 



well composed and neatly printed, and deserves the patron- 

 age of the public. The article, Military Bounty Tracts p, 

 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 mistake 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 

 of the Mississippi, whose velocity is generally estimated 

 from three to four miles, and by Dr. Beck, from two to 

 four miles an 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 be 

 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. Missiasippi River, in the New Edinb. Encyc. 



