Their trip to Pedro Miguel was devoid of incident.  At those locks, instead of “going up stairs” they went down, the level gradually falling so their boat came nearer to the surface of the Pacific.  A mile and a half farther on they would reach Miraflores.

The tug had approached the central pier, to which it was tied, awaiting the services of the electrical locomotives, when back of them came a steamer, one of the first foreign vessels to apply to make the trip through the Isthmus.

“That fellow is coming a little too close to me for comfort,” Captain Watson observed as he watched the approaching vessel.

Blake and Joe, who were standing near the commander at the pilot house, saw Mr. Alcando come up the companionway and stand on deck, staring at the big steamer.  A little breeze, succeeding a dead calm, ruffled a flag at the stern of the steamer, and the boys saw the Brazilian colors flutter in the wind.  At the same moment Mr. Alcando waved his hand, seemingly to someone on the steamer’s deck.

“Look out where you’re going!” suddenly yelled Captain Watson.  Hardly had he shouted than the steamer veered quickly to one side, and then came a crash as the tug heeled over, grinding against the concrete side of the central pier.

“We’re being crushed!” yelled Blake.

CHAPTER XVII

THE EMERGENCY DAM

The crashing and splintering of wood, the grinding of one vessel against the other at the concrete pier, the shrill tooting of the whistles, and the confused shouts of the respective captains of the craft made a din out of which it seemed order would never come.

“If I could only get this on a film!” said Joe to himself during a calm moment.  But the cameras were below in the cabin, and the tug was now careened at such an angle that it was risky to cross the decks.  Besides Joe must think of saving himself, for it looked as though the tug would be crushed and sunk.

“Pull us out of here!” yelled Captain Watson to the man on the lock wall in charge of the electrical towing locomotives.  “Pull us out!”

That seemed one way out of the trouble, for the Nama was being crushed between the Brazilian steamer and the wall.  But the order had come too late, for now the tug was wedged in, and no power could move her without tearing her to pieces, until the pressure of the big steamer was removed.

So, wisely, the men in charge of the towing machines did not follow Captain Watson’s orders.

“Over this way!” cried Blake to his chum, and to Mr. Alcando, who were standing amid-ships.  Joe was at the bow, and because that was narrower than the main portion of the tug, it had not yet been subjected to the awful pressure.

But there was no need of Joe or the others, including Captain Watson, changing their positions.  The Brazilian ship now began drawing away, aided by her own engines, and by the tow ropes extending from the other side of the lock wall.  The Nama, which had been partly lifted up in the air, as a vessel in the Arctic Ocean is lifted when two ice floes begin to squeeze her, now dropped down again, and began settling slowly in the water.