Part 15 (1/2)

ALMOST AN ACCIDENT

”What's that big, long affair, jutting out so far fro had approached nearer

”That's the central pier,” the captain inforuide wall, to protect the locks You know there are three locks at this end; or, rather, six, two series of three each And each lock has several gates One great danger will be that powerful vessels e them, and, to prevent this, very elaborate precautions are observed You'll soon see We'll have to tie up to this wall, or we'll run into the first protection, which is a big steel chain You can see it just ahead there”

Joe and Blake, who had gotten all the pictures they wanted of the approach to the lock, stopped grinding away at the handle of the cah to look at the chain

These chains, for there are several of theate, consist of links made of steel three inches thick They stretch across the locks, and any vessel that does not stop at thethis chain, will ra any such chances,” Captain Watson inforht happen, and I don't want to injure my boat”

”What would happen if you did hit the chain?” asked Blake They had started off again, after the necessary pernaled to the the chain in position

”Well, if I happened to be in co vessel, say the size of the _Olympic_, and I hit the chain at a speed of a mile and a half an hour, and I had a full load on, the chain would stopthe lock gate”

”But how does it do it?” asked Joe

”By means of machinery,” the captain inforoes about a drum, which winds and unwinds by hydraulic power Once a shi+p hits the chain its speed will gradually slacken, but it takes a pressure of one hundred tons to in to yield Then it will stand a pressure up to over two hundred and fifty tons before it will break But before that happens the vessel will have stopped”

”But we are not going to strike the chain, I take it,” put in Mr

Alcando

”Indeed we are not,” the captain assured hi lowered now”

As he spoke the boys saw the immense steel-linked fender sink down below the surface of the water

”Where does it go?” asked Blake

”It sinks down in a groove in the bottom of the lock,” the captain explained ”It takes about oneto raise it”

”Well, I've got that!” Blake exclai He had sufficient views of the giant fender As the tug went on Captain Watson explained to the boys that even though a vessel should e to break the chain, which was almost beyond the bounds of possibility, there was the first, or safety gate of the lock And though a vesselto failure to stop in the lock, there would be a second gate, which would al the craft to a stop

But even the ht of by the ates be torn away, and the impounded waters of Gatun Lake start to rush out, there are eency dams that can be put into place to stop the flood

These e into place in two minutes by means of electrical machinery, but should that fail, they can be put into place by hand in about thirty minutes

”So you see the Canal is pretty well protected,” re across the place where the Chain had been, and so into the first of the three lock basins

”Say! This is great!” cried Blake, as he looked at the concrete walls, towering above hih