Physics and Hydraulics of the Mississippi River. 187 
navigated with boats drawing three feet of water, up to the point 
where it issues from the mountains, from the middle of May to 
banks—changes of the bed—oscillations of the Gulf, and their 
effects upon the lakes and river—tidal oscillations of the river 
—hurricanes and their effects—range of the Mississippi between 
high and low water—elevation above the gulf—of the surface of 
the river—usual succession of stages—dimensions of cross-section 
~Jyearly amount of rain in the basin—annual discharge of the 
ISsissippi and its principal tributaries—ratio between rain and 
drainage in the basin—sedimentary matter in the Mississippi 
v ] different states—di an 
fy—levee organization in the different state imensions 
and cost of kinked levees—the earlier floods and those of 1828, 
1844, 1849, 1850, 1851, 1858, and 1859. But we have room for 
the following extract only, from page 178 
and occasioned much damage by flooding the small streams, 
They also prevailed west of the Ohio basin and caused a rapid 
mt. These rains continued, especially in the 
Thdiana, iinois, on viene me he Miami, Wabash, and 
‘NOis rivers to unprecedented heights, and filled all the lower 
'nbutaries of the Missouri. The usual June rise of the latter 
v8, Oceasioned by the melting of snow in the Rocky moun- 
tains, and the spring and early summer rains along its course, 
amounted ee 8 jos 
city of “ea cubic feet per 
