244
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I expenditure in attempts to make good any weakness due to the use of inferior material. Portland bement sets best in water, and consequently is the safest material
I to use to resist water.
In the construction of the Dam the inner faces of concrete, respectively 7 to 1 and 5 to 1 must be
made absolutely water-resisting, that is, the materials must be enriched and grouted with pure liquid
cement, layer-by- layer until this portion of the
work forms
one solid body through which water,
under the greatest pressure, cannot filter. I cannot
impress this too strongly upon the attention of the
ordinarily
Surveyor General, as I know that concrete, as
used in heavy Dock walls not more than half the
height of this Dam, is not water-tight. For a =
whilst
Dock wall this is not of vital importance,
in a Reservoir Dam it is all important.