THE SALTON SEA—NEWELL. 343 
train load after train load of small stone and gravel from the nearby 
hills were dumped to fill the spaces between the large rocks. 
Finally, after days and nights of struggle, the water was raised 
to a point where it began to flow down its former channel and less 
and less to pass over the top of the rock heap. Then finer material 
was added and rapidly piled up on the accumulated rock mass. The 
lower side of this loose rock dam is shown in Pl. VIII. On the far 
side beyond the rock dam and the railroad trestle is the river, as 
indicated by the steamboat lying alongside of the track. 
At first a large amount of water passed through the rock heap and 
steps were taken as rapidly as possible to close the openings by dump- 
ing sand and gravel, finishing this work by hydraulicking silt or mud 
over the area, and washing this in with a hose. By thus piling up 
finer and finer material and distributing it, the seepage or percolation 
through the rock mass was quickly checked and the barrier became 
effective. 
The next step after having turned the water back into the main 
channel was to perfect the great dam of loose rock and gravel, cover- 
ing it up with a mass of earth and protecting this in turn by gravel, 
so that the burrowing animals could not make holes through the bank 
and thus afford opportunities for the water from the floods to under- 
mine the finished work. 
As now completed, there extends from the head works in the 
United States along the river, between it and the canal, a double 
row of dikes, the outer one being occupied by a railroad. These 
extend in an unbroken line for a dozen miles near the river and 
shut it off from the lowlands to the west. The river side of this 
dike is protected by a thick layer of gravel, and the railroad affords 
immediate access to all parts, so that if menaced by the cutting of 
the banks it will be possible to bring men and materials to check 
the floods from encroachment upon the dike itself. 
Secondary dikes or cross levees run from the main structure to 
certain subsidiary works, so that if the outer main dike is broken or 
water flows through, this will be ponded for a while at least against 
the inner line of defense, thus affording time to assemble the neces- 
sary equipment to fight another intrusion. 
The water needed for the irrigation of lands in the Imperial 
Valley comes through the permanent head works in the United 
States, follows down behind the dikes in the channel dug for the 
purpose and then passes down the bed of the Alamo, enlarged during 
1905 and 1906. It continues to a point where it is diverted into the 
canals of the settlers as before described. 
The immediate danger of any further breaks appears to be done 
away with, although there are rumors from time to time that water 
41780—08——26 
