would hardly be putting in the elevators before the building was started.”
“Maybe he meant next door, in that sky-scraper,” I suggested.
Fortunately, the elevator starter of the next building happened to know the Mr. Williams for whom we were looking, and sent us back to the adjacent lot. “You will find Williams on the job over there, He is superintending the driving of the deepest bore on record.”
That puzzled us all the more, as we could n't see, for the life of us, what that had to do with the construction of an elevator. Sure enough, when we got there inside the fence and were directed to Mr. Williams, we found that he was overseeing the sinking of some sort of a shaft. A jolly individual he was, exceedingly fat, and well bespattered with mud. He waddled over to us, looked at our card of introduction, then shook us heartily by the hand.
“So you ‘ve come over to see how we dig a hole, have you? We are down two hundred and sixty feet in one shaft, and we still have to go one hundred and five feet more; three hundred and sixty-five feet, think of it! How is that for a hole, and only twelve inches in diameter, too?”
“But what has that to do with elevators?” we asked.
“Why, this is ta be a plunger-elevator. Did n't Mr, Hotchkiss tell you?” Then Mr. Williams explained to us how the thing worked.
Probably most of the boys who read this story know what a plunger-elevator is, but we were rather green, and had to be told. “In each of these deep holes,” explained Mr. Williams, “we are going to fit a steel cylinder, nine inches in diameter inside, and closed at the bottom. Within the cylinder there is to be a plunger six and one half inches in diameter. The plunger is going to pass through the stuffing-box at the top of the cylinder, just like the stuffing-box of a steam-cylinder where the piston comes out. The plunger is fully as long as the cylinder, and upon it the elevator car is mounted. Now, when water is let into the cylinder under pressure, it forces out the plunger, raising the car. What surprises most people is that the plunger does not have a piston-head on its lower end, but is merely a straight piece of steel tubing down to the very bottom, where it is closed with a cap, and has two or three guides on it to keep it centered in the cylinder. When the water is forced in, it exerts a pressure in all directions on the cylinder as well as on the plunger, but nothing can yield to that pressure except the bottom of the plunger, which is raised, and so pushes the elevator car up. I will take you over to the next building and show you the whole thing in a minute, as soon as you have seen how we sink the shafts.”
HOW A PLUNGER-ELEVATOR IS BUILT.
They were hauling up one of the boring tools just then. It was on the end of a cable attached to a “jumping” machine. Slowly the cable was wound up, and the length of time it took to raise the tool gave us some idea of the enormous depth to which the shaft had already been sunk. When the tool finally came up, we found that it was flat, with a cutting edge something like a chisel. It was pretty badly worn, and a newly sharpened one was put in its place; then down went the tool into the long, deep bore. When it reached the bottom, the line was pulled up until the tool scarcely touched, after which the machine was started, and drilling was resumed. Mr. Williams told us that the tool would not be allowed to hit the rock with hammer-blows like a pile-driver, for it would be sure to turn off sidewise and follow a seam or a fault, making a crooked hole. Instead, the tool was dangled so that it just barely touched, then, as it was jumped by the machine, the stretch of the cable at each yank would let it strike the rock with a light, springy blow that could not turn out of line; at each blow of the tool it was turned around slowly, so that it would pound out a circular hole. The rock dust was carried to the surface by forcing water into the bore, so that it was a rather mussy job.
“Before we came to solid rock,” explained Mr. Williams, “we had to go through about eighty feet of sand, and the boring was then done with a water jet. This steel tubing,” he said, pointing to the lining of the hole, “was sunk into the sand by forcing water at high pressure against the sand through a jet placed in theVol. XL.—104.
