NEW METHOD

This being the case, one builds upon this foundation a sloped stone structure (dos-d'âne)original: "Dodane"; a ridged or pitched stone surface, literally "donkey's back," used to divert water flow and protect the base of a structure., the profile of which is demonstrated in this 4th Figure, in which A, B, C, D, E, and F have the same meaning as in the 1st Figure; and furthermore, the dovetail pilesoriginal: "pieux à queuës d’arondelle"; interlocking wooden stakes that fit together like a joinery joint to create a continuous, sturdy barrier. B G and C H are applied there. In this Figure, it is shown how the aforementioned two causes are provided against; for even if a depth of 20, 30, or 40 feet is scoured out in front of the slope, as long as the piles still remain three or four feet within the sand, the base of the slope remains intact. And after the high water has subsided, the river is ordinarily inclined to deposit sand into that depth, just as it was before. As for the second cause—the great pressure of water which ruins the foundation—that is also prevented here; for if the slope were to receive any seepage from beneath, it would have to pass under the dovetail piles, near G and H, but that is not quite possible because of the massive body of clay and sand from B to G, from G to H, and also from H up to C, which would have to be moved at such a great depth. And even if the earth were dispersed from B to near G, the great quantity of sand from B to H, and from H up to C, could not easily be moved.

As for what someone might say—that when the depth in front of the piles from B to G becomes greater than the length of the piles, and the dispersal of the sand reaches further under the slope, destroying the foundation, then the slope along with the piles and everything within must fall—the answer to this is that there is a great difference between a foundation like this one, which can only be destroyed by an initial deep ruin, and a foundation which is destroyed simply by pressure without preceding ruin, like that of the 1st Figure. Furthermore, it rarely happens that such ruin reaches as deep as the length of long piles.

I have indeed declared this opinion of mine regarding dovetail piles to some Engineers, which has resulted in boards being driven 3 or 4 feet deep in these lands before certain buildings at the water's edge—boards only two inches thick with triangular grooves fitted into one another. But such thin boards cannot withstand the pile-driveroriginal: "hie"; a heavy mechanical hammer used to drive stakes into the earth. to reach the necessary depth; my intention is for such dovetail piles as I have described previously.