"Of course, piles can be sunk by water pressure from a floating stage such as a barge, pontoon, or raft, so long as the pile is kept vertical, but there are the same objections to that method as with other piles. Piles are, however, got down much quicker and easier by the water jet than by screwing or driving, but the ground must be loose granular soil, such as ordinary sand.
"There is not much 'extra' to be got out of iron piles. You can only dodge a bit with a length short now and then when you have the right parties to work with, and the inspector is cross-eyed or a star-gazer, but you may get something 'extra' out of the filling them in. As usual I draw the line somewhere. Everything on earth has a boundary line. This is where I draw it. Listen!
"After as much water as possible—possible is a nice elastic word—is got out of the pile, and it is as clear of deposit as convenient—another nice easy word—and before commencing the filling, I put inside the pile everything I can get hold of that is dry, for just then I have but one way of looking at anything, and that is to consider it Portland cement concrete, unless it costs me more to use it; but when the filling is concrete, I make that as dry as mixing will allow, and sometimes hardly that. The inside of the pile is sure to be wet, and that will help the mixing. I never ram the concrete, but gently cast it in. It is only a sort of anti-rust covering, and is put in for that and to keep water out, and no weight comes upon it—it is not like the hearting of cylinder bridge piers. Ramming the concrete is not far from being a mistake, because the pile should have a chance of contracting without straining, and may be it will crack; and it is just as well to remember that although by ramming tightly you may get more solid filling and better protect the inside from rust, the pile may be strained, and it is a choice of evils, possible rust, or strain."
CHAPTER V.
TIMBER PILES. PILE-DRIVING.
General Consideration.
"Now, as promised, I will tell you of a little bit of free trade with some timber pilework."
"That's it. I am waiting for it."
"Well, they let me have 400 feet run of pile-driving. Double row of 16 to 12 inch piles, and there were some fine sticks nearly 55 feet long, and that is a long length for a sound pile, and you have to pay for them."