Part 15 (2/2)

Now the tug no longer side the wall of the central pier For all vessels h the lock basins, and towed not by other craft, but by electric locoside, on the top of the concrete walls

Two of these loco, and two to the stern But those at the stern were not for pulling, as Joe at first supposed, for he said:

”Why, those loco fast to us ire hawsers I don't see how they can push with those”

”They're not going to,” explained Captain Watson ”Those in the stern are for holding back, to provide for an eency in case those in front pull us too fast”

”Those who built the Canal see,”

spoke Blake with much enthusiasm

”You'll think so, after you've seen so captain went on with a set your ca and closing the gates for us now, and that ought to ood pictures, especially e are closed in the lock, and water begins to enter”

”How does it come in?” asked Joe ”Over the top?”

”No, indeed They don't use the waterfall effect,” answered Blake, who had been reading a book about the Canal ”It comes in froh valves that are opened and closed by electricity In fact everything about the lock is done by electricity, though in case of eency hand power can be used The water fills the lock through openings in the floor, and the water itself co!”

The boys sahat seemed to be two solid walls of steel slowly separated, by an unseen power, as the leaves of a book ates of the locks are called ”leaves” Slowly they swung back out of the way, into depressions in the side walls of the locks, o!” cried the captain, the tug began to move slowly under the pull of the electric locomotives on the concrete wall above them ”Start your ca Already the handles were clicking, and thousands of pictures, showing a boat actually going through the locks of the Pana strip of sensitive film

”Oh, it is wonderful!” exclaimed Mr Alcando ”Do you think--I mean, would it be possible for me to--”

”To take soenerously

”Here, grind this crank a while, I'iven so picture camera, and he knew about at what speed to turn the handle For thepictures must be taken at just a certain speed, and reproduced on the screen at the sarotesque Persons and animals seem to run instead of walk But the new pupil, with a little coaching froates will be closed,” said the tug captain, ”and the water will coher lock We have to go through this process three times at this end of the Canal, and three ti gates were not yet fully closed when so happened that nearly put an end to the trip of the , instead ofbackward, toward the slowly-closing lock gates

”What's up?” cried Blake

”We're going backward!” shouted Joe

”Yes, the stern loco us back, and the front ones seeo!” Captain Watson said ”We'll be between the lock gates in anothertoward the top of the lock wall ”What's the ates If she once got between theshell And it seereat, steel leaves

”This is terrible!” cried Mr Alcando ”I did not count on this in learning to hter places than this,” said Blake, as he thought in a flash of the dangers he and Joe had run

”What'll we do?” asked Joe, with a glance at his chuh we'd have to swim for it if the boat is smashed,”

said Blake, who re swi tank, anyhow, but if they let the other water in--”

He did not finish, but they knehat he ates were closing and now the tug had almost been pulled back between them She seemed likely to be crushed to splinters