THE SPOIL OF THE LOCKS.
At eleven o'clock that night the workmen employed at the locks, the
spillway, and the barrier of the Gatun dam found that their lights were
not working satisfactorily and sent word back to the electric department
that something was amiss.
The electric department sent word back to the men in the excavations that
the lights were all right so far as they were concerned, that they were
doing their full duty efficiently, and that the men with the shovels, the
dynamite and the dump cars might go chase themselves.
This expression of fact and permission did not make it any lighter at the
workings, but the men kept on, in the intermittent showers of
illumination, and grumbled while they excavated and piled in the concrete.
At last, just before midnight, the incandescence did not come back to the
globes, and the men gathered in groups to discuss the matter and express
heated opinions of the efficiency of the men in charge of the lighting
plant.
The workmen moved about here and there in the shadows and clambered like
ants over the great bulk of the dam. No one looked to see that the men
assembled in the workings all belonged there. At midnight four men who did
not belong there entered the excavation which leads from the bottom of the
lower lock to the sea-level channel into Limon Bay, which is a child of
the Caribbean Sea.
These four men moved about as if accustomed to the situation, only now and
then they halted and whispered together. Other men, workmen, were doing
that, however, and so these four passed on up to the foot of the spillway
without attracting attention.
Here they separated, one to the west, one to the east, where the locks
are, and one to a position half way between the spillway and the west side
of the locks. The fourth man remained near the foot of the spillway.
Due primarily to its size, Gatun dam has received, perhaps, more attention
in the United States than is its due. There is nothing especially
difficult or complicated about this dam, and many dams have been
successfully built in this country to withstand much larger pressures and
greater heads of water than the Gatun dam without being given one-quarter
of the attention.
Gatun dam fills the opening between the hills at Gatun through which the
Chagres river flows to the Caribbean Sea. It consists, if it may be
regarded in the light of a finished production, of a water-tight center or
core composed of sand and clay mixed in proper proportion and deposited
hydraulically; that is by being pumped in.
On each side a wall of rock confines this core. The bulk of the dam rests
on impermeable material of sufficient supporting power. The locks and
spillway are considered a part of the dam.
The locks are built in an excavation at the east end of the dam, in rock,
and will lift vessels from the Atlantic level to the level of the Lake of
Gatun. The spillway is a concrete-lined opening cut through a hill of rock
near the center of the dam. When supplied with suitable gates, it will
regulate the level of the lake.
The dam proper is about 9,000 feet long over all, measured on its crest,
including locks and spill way, but for only five hundred feet of this
great distance will it be subjected to great pressure. During this space
there is, or will be, a weight of about eighty-five feet depth against the
barrier. For only about half its length will the head of water on the dam
be over fifty feet.
It will be seen from the above description that the point of attack on the
dam would naturally be where the pressure is greatest, also at the locks,
which would make a mighty channel for the flood of water, and which would
be difficult to repair. The spillway, too, if enlarged by explosives,
would make a nasty hole to build up.
Now another point which Ned had considered when he looked over the crude
drawings he had discovered. Hard rock underlies the dam near the surface
of the ground except for about one-fifth of its entire length. Here the
rock dips down to a minimum depth below sea-level of from 195 feet in the
depression east of the spillway to 255 feet in that west of the spillway.
Here, of course, would be another point of attack by one designing
permanent mischief.
These depressions or valleys have been slowly filled during past ages.
Measured from sea-level down, the first 80 feet consists of sand and clay;
the next 100 feet or so is stiff blue clay, while the last 20 to 60 feet
is a conglomerate, composed of sand, shells and stone. It will be readily
seen that great damage might be done by a raging torrent boring into the
sand and clay of the first strata.
Now, the outer walls of rock are 1,200 feet apart, the interval being
filled with spoil from the canal and lock excavations. The south "toe," as
it is called, has a height of 60 feet, while the north or down-stream
"toe" is 30 feet high. Spoil from the excavations will be dumped outside
the "toes" until the dam is 2,000 feet in width at the bottom. The top of
the dam is, or will be, 30 feet above water level and have a width of 100
feet. The channel of the spillway is 300 feet wide.
Ned had figured it out that one attacking the dam would naturally seek to
enlarge the locks and the spillway and also to burrow in under the bulk of
the dam where the sand and clay had been washed in below sea-level by
countless years of flood and storm. The locks and spillway, enlarged,
would require years of active work for repair; the sand and clay, if
subjected to high explosives, would cause the crest of the dam to drop in
on the north side and so enfeeble the entire structure, requiring the
gigantic work of constructing new foundations.
Therefore, when Ned saw the four men moving toward the spillway, saw them
part and seek the vulnerable points which have been described above, he
knew that the time he had been waiting for had come. The treacherous
rascals were there to do their wicked work that night--to carry out plans
long formed and well considered--and they were opposed only by the
inexperienced patrol leader from New York and his three chums, Frank Shaw,
Glen Howard, and Peter Fenton. It will be remembered that Jimmie McGraw,
Jack Bosworth, and Harry Stevens were at the old stone house on the road
to Las Cruces from Gamboa, and that George Tolford had accompanied Tony to
the Chester camp.
On reaching Gatun the boys had slipped out of the lights of the station
and descended immediately to the bottom of the cut. They were at once
accosted by a foreman, but the explanation Ned gave seemed more than
sufficient, for Dan Welch, the man in charge of a group of workers on the
locks, at once summoned his assistant to the job and remained with the
boys.
"I have heard about you, Ned Nestor," Welch said; "in fact, about half the
men in the workings at Gatun have heard of you."
"I don't understand how," replied the puzzled boy.
"Well, through that bomb business at the cottage. You see, it leaked out.
When the attempt to blow up the place was reported, the men naturally
asked what the dickens the scamps wanted to blow up a crowd of sightseers
for, and then it came out that you came here with Lieutenant Gordon, and
that's about all."
It was at this time that the lights suspended operation. Welch glanced
about the busy scene for an instant and sat down on a box which contained
tools.
"No use," he said. "The electric men work as they please. We'll wait here
and lose our record. Did you say where Lieutenant Gordon is to-night?"
"I did not, because I wasn't asked," was the reply, "and because I don't
know where he is."
"He's a good fellow, Gordon," Welch exclaimed. "I'd go far and fast to do
him a favor. I hope he's coming out of this game all right."
Then Ned sat down on the tool-box and told Welch the story of the
abduction of the lieutenant, and also the story of what was going on there
that night, as he understood it. To say that Welch was profoundly excited
does not half express the foreman's state of mind as he listened.
"My God!" he cried, when Ned paused. "To think of the wickedness of the
thing. To destroy the work of years. To delay the completion of the canal
for a decade. What can we do? In this darkness, the spoilers can work
their will."
"I think I know who they are," Ned said. "We must find them."
"It is too bad that the lights should fail us just at this time," the
foreman said.
"I have an idea that the plotters arranged for that," Ned said, then.
"But how?" demanded Welch. "The plants are well guarded. You know, of
course, that we are all on the lookout for something of the kind? We
thought we had provided against any sudden surprise. Where are we to look
for them?"
Then Ned pointed out the probable points of attack, and Welch sprang to
his feet in a fuming passion.
"The spillway and the locks," he cried. "And the point where the soft
earth extends under the dam! Come!"
"Bring four of your men who can be trusted," Ned advised, not leaving the
box.
"Yes, and what then?"
"Send a man to the light station and have tracers sent out, but instruct
him not to have the lights turned on until you give the signal."
"I understand," the foreman said. "We'll catch them with the goods!"
Four men, workmen, were strolling along the danger points within five
minutes, and another moved toward the electric switches which governed
that part of the illumination. Ned and Welch remained near the spillway.
The three boys, after whispered instructions from Ned, moved along the
line passing word from man to man.
It was a long and heart-breaking half hour, seemingly double that time,
that followed. The man from the switches came back and whispered to Welch,
and at that moment a shrill bird-call sounded in the darkness. This, in
turn, was followed by the report of a revolver, and then the light leaped
into the globes, making the place, the entire length of the canal dam, the
spillway and the locks, as bright as day.
There came a half-hearted explosion from the direction of the locks,
followed by more shots. Then everything was in confusion, and groups of
men gathered in four spots along the line. There were more shots and then
the three boys rushed, panting, to the position Ned and the foreman had
taken.
"They've got them!" Frank cried. "They've got every man of them--four Japs
with lighted fuses in their hands!"
"There must be more than four!" Welch cried.
"I think not," Ned replied. "This is hardly a job for many men to work on!
The four dare not take others into their confidence. Come! Suppose we
gather them in?"
"How do you boys know they've got them all?" demanded Welch. "The four men
must be some distance apart."
"Not too far for a revolver to carry a signal!" smiled Ned. "You probably
noticed four groups of shots? Well, the boys who have been acting as
messengers from man to man gave directions as to the number of shots for
each group!"
"I see!" said Welch. "You don't need any whiskers, boy, to do the brain
work of a man. Here comes the first batch!"
Itto and Gostel were the first ones brought in. Itto was wounded fatally
and Gostel was bleeding from a wound in the side. The other men were not
injured. They stood in a little group for a moment, and then Itto dropped
to the ground.
The reports of the men who had been sent out to the danger points showed
that each one of the four had been caught lighting a fuse, the bombs
having been set.
"We were forced to work before we were ready," Gostel said, defiantly.
"Our government discovered what was going on, and we would have been
arrested to-morrow. So we were obliged to take the risk to-night. We were
working for the glory of the Emperor, but he forbade it!"
"I did not believe the government of Japan would descend to any such
despicable work," Ned said. "You fellows are cranks! You would have worked
great harm to your Emperor if you had succeeded. By the way," he added,
"what did you do with Lieutenant Gordon?"
Gostel glared at his questioner, but Itto beckoned Ned to his side.
"The old stone house on the road to Las Cruces!" he whispered.
"Where is that?" asked Welch, who had bent over the wounded man and heard
the words.
"I know," replied Ned. "One act of this tragedy has already been pulled
off there. Have your men take these cranks to Gatun and get a railroad
motor. We must get to Gamboa without loss of time. It is only a short
distance from there to the place he speaks of. If they took Lieutenant
Gordon there a prisoner, they are likely to have had a warm reception, for
three of my chums are there!"
But it was not necessary for them to go to the old stone house. At Gamboa
they found Lieutenant Gordon and the three boys. Jimmie excitedly related
the sensational occurrences at the house.
"Jack and Harry came up," he concluded, "just as the two men, Pedro and
Gaga, were going together with knives. I was scared into a trance! The
boys covered them with guns an' we trussed 'em both. You never saw people
more surprised in your life. Then two men brought in Lieutenant Gordon,
all nicely tied up, and went away, or started to go away. Well, they
wasn't prepared for an attack from the bushes, and we have four prisoners
in a cell of a jail at Gamboa, right over there!"
In an hour the boys were all back at Culebra, with Lieutenant Gordon
looking angry enough to eat sinkers, as Jimmie said. The officer though
pleased at the general results, did not like to admit that he had been
captured by the enemy and rescued by the Boy Scouts, the little fellows he
was guarding!