This width of flooring was doubled to 223 ft., and along the upstream face a line of sheet piling was driven 16 ft.
The mooring chains, weighing 22 lb per ft., are taken from the upstream end of each pontoon to a downstream screw pile mooring and from the downstream end to an upstream screw pile.
In one of these papers Levy formulated the requirement now generally adopted in France that the vertical pressure at the upstream end of any joint, calculated by the law of uniformly varying stress, should not be less than that of the water pressure at the level of that joint in order to prevent intrusive water getting into the structure.
This feature indicates that in the event of a crack occurring at the upstream toe, its extension would tend to turn downwards and follow a direction nearly parallel with the maximum pressure lines, in which direction it would not materially affect the stability of the structure.
The recent investigations already referred to indicate the desirability of curving dams in plan in order to reduce the possibility of tension and infiltration of water at the upstream face.
The Missouri is navigable for small boats to Fort Benton in Chouteau county, but farther upstream near Great Falls, Cascade county, to which it is navigable at high water, it falls 512 ft.
A blue-green tint shone through the sunlight while frozen waterfalls, hanging from the upstream cliffs, bore a hint of the rust-orange hue from the natural deposits of Red Mountain above.
The easterly winds, which are deflections of the trade winds, blow upstream with great regularity and force, more especially in the winter or dry season, and are felt as far inland as the mouths of the Madeira and Negro.