188 Physics and Hydraulics of the Mississippi River. 
was the actual reservoir capacity of that region that the chan 
nels of the six large bayous, and of the St. Francis itself, were 
insufficient to give water-way to the flood, returning to the Mis 
sissippi. For miles above Stirling, it poured over the 
themselves, washing the remains of the levees into the river. It 
passed like a great wave through the swamp, causing the deep- 
est overflow ever known. Collecting again, in this manner, at 
Helena, in about two weeks after it entered the alluvial region, 
it poured with renewed force upon the lower country. In the 
pent were comparatively empty, owing to the general resistance 
cient to carry off the limited amount of crevasse water, and dis 
charge it into Black river, whence it passed down bayou Atcha 
a. Below Red river landing, the levees remained unbroken 
except at the Belle and LaBranch crevasses which submer, 
e country between the Mississippi and bayou LaFourehé. 
Fortunately , the upland tributaries below the Ohio were all low 
during this great rise, for to this circumstance alone is due 
eseape of the lower country from general overflow 
ood. A 
e year. 
_ The third chapter presents the state of the science of Hy draul- 
les as applied to rivers. The topics are the early history. of Oy 
sia: we 
Ts. 
_ “The solution of that great problem, the best method of pre 
venting the overflows of the Mississippi, exacted difficult pore 
urements and extremely intricate computations. In connect” 
with it, a careful examination of all writings upon hydra 
hat were within reach was made, to ascertain precisely the Pr 
ent state of that science; a list of the principal publication” 
upon the subject, with a brief synopsis if Ahan parts of thet 
