Physics and Hydraulics of the Mississippi River. 189 
contents that are connected with the veers pre a been 
e found from this that 
edge of those laws was essential to the determination of the 
Plans of protecting the Mississippi valley from inundation, the 
Investigations of the Delta Survey, conducted with that object, 
In es ape it, have necessarily contributed to the advance- 
ydraulics. An account of these investigations will be 
presented in full detail in the two following chapters. This chap- 
teris devoted to a brief notice of publishe works, which is 
Partly original and partly compiled from similar notices by 
Rennie, Lombardini, Storrow, and others, and from various en- 
cyclopzedias,” : 
e following are some of the subjects discussed in the fourth 
chapter on the method of guaging the Mississippi, its tributaries 
and its crevasses :—Method of determining dimensions of cross- 
seclion—method of conducting velocity measurements—compu- 
tation of discharge, neglecting change of velocity below the 
Tvers by formule, &e.; chapter sixth, protection ainst the 
‘oods of the Mississippi ; irate seven, Delta of the Missis- 
Sippl; chapter eight, mouths of the Mississippi—bars at the 
Mouth and plans for increasing the depths of the bars, &c. 
he preceding extracts convey but an inadequate idea of the 
£xtent and importance of this work. Many portions of it can- 
not be 
found 
shall take care fo transfer to our pages under the proper heads 
to the credit of the general ent 
Wed an 2 governm ‘ | 
pul .48 &@ model for the style of its future scientific and military 
lications, e 
