Directly they gained the submarine, the hatch was placed quietly in position for prompt closing and the lines which held the boat were let go.
Owing to the movement of the boats caused by the roughened surface of the harbor creakings and groanings of the fenders had served to drown any noise the party had made in crossing the narrow bridge of planks.
Jimmie held the wheel as Ned gave the signal for casting off the lines. A touch of Harry"s hand on the lever started the engines. The submarine began to move. Suddenly a loud splash alongside attracted the attention of all. Frank came scuttling down the ladder.
"Now I"ve done it!" he gasped. "I forgot to shove the plank back onto the next boat and it fell into the water as we started!"
"Wonder if the guard has heard it!" speculated Ned. "Let me up!"
Under protests from his companions the lad mounted the iron ladder and thrust his head through the hatch.
"I hear someone running along the dock!" he announced presently. "I"ll bet they have heard that noise! I see a light!" he added.
"What are they doing?" inquired Jimmie, holding the boat directly in the center of the channel as he peered anxiously ahead.
"A fellow with a lantern is running out along the planks," replied Ned.
"They"ve got to the outside boat now. Now they"re turning back."
"Better get that hatch closed so we can dive," admonished Jimmie. "This is our time for getting out of sight in a hurry!"
"There goes their searchlight!" shouted Frank, who had crowded up the ladder close beside Ned. "They"re going to spot us in a hurry!"
"Ah," cried Ned as a sullen roar came to their ears. "They"re taking a chance shot at us from that cannon on the hill. Let"s dive!"
Quickly the two boys adjusted the hatch. As they signaled to their companions that this task was completed Harry and Jack turned the deflecting rudders. The half-manned submarine slowly began to descend.
"Get some water into the tanks quick, Harry!" called Jimmie.
"Pump"s going right now!" declared the other. "We"re going down!"
"Take a look through the periscope, Ned," requested the pilot, "and let me know what you can make out. Can you see any buoys ahead?"
"Try to see if they"ve located us with their searchlight," suggested Mackinder. "Maybe they are getting our range with that gun!"
"Never mind about that searchlight," snapped Jimmie. "I want to find out what"s ahead, not what"s behind us. We"ll run this boat!"
"I simply wanted to know," objected Mackinder somewhat ruffled at the lad"s peremptory manner. "No objection, is there?"
"All the objection in the world!" declared Jimmie. "You"re quite welcome aboard as a pa.s.senger, but we"ll navigate the vessel, please!"
Scarcely knowing whether to be amused or defiant at this att.i.tude Mackinder chose the wiser course and refrained from further comment.
Although the boys could not be sure that the persons on the island were making efforts to hinder their escape they felt the better course was to remain beneath the surface until well out of the harbor.
Directly Jimmie called the attention of his comrades to an object in the water at no great distance ahead. The rays of the searchlight with which the submarine was provided indistinctly revealed a huge bulk slightly above the level at which they were traveling.
"What is that, a ship?" asked Harry wonderingly.
"I"ll bet a cookie that"s a mine!" declared Jimmie positively. "I"m going to give it a little more leeway, anyhow. It pays to be safe!"
Ned was working the periscope in an effort to locate the buoys as directed by Jimmie. Occasionally he turned the gla.s.s toward the group of buildings they had just left.
"They"re shooting at us, I guess!" he stated presently. "I can see the flash of that cannon. It seems to be pointed this way!"
"Let "em shoot, they can"t see anything but the periscope and they"d have an awful time hitting that!" boasted Jimmie.
Scarcely had the lad spoken before the vessel was shaken by the force of a mighty concussion. A gigantic wave tossed the craft up and forward with a heave that threw the boys off their feet.
"What was that?" gasped Jimmie glancing at his companions with a terrified face. "Has one of the fuel tanks blown up?"
"Nothing doing!" replied Harry. "I think that cannon hit the mine we just pa.s.sed. I"m glad we were no closer!"
"We"ll soon be out of their range!" stated Jimmie. "Shut up your periscope and we"ll go deeper. Give us a little more speed, Harry!"
In an hour Jimmie declared that they should be out of sight of the island altogether. The engines had been working at full speed ahead. Harry nursed the machinery constantly, knowing that it was new and would, therefore, require considerable care. Their urgent need for speed induced the lads to crowd the machinery to the limit, and Harry was gratified to note that every part responded properly to its task.
"Well, Mackinder," stated Ned as the tension on their nerves began to relax with the increasing distance traveled, "we"re surely grateful to you for suggesting that we get away as you did!"
"My motive was largely a selfish one, I must confess," returned Mackinder. "I wanted very badly to get away from that island."
"How did they ever get hold of you, anyhow?" questioned Jack.
"I left Amsterdam the same evening you did. After the Lena k.n.o.bloch went past us as she did I knew there was little use trying to delay you.
Therefore, my aide and myself left at once on a train for Rotterdam.
There we found a fishing boat which we thought would answer our purpose.
We induced the captain to take us aboard, intending to cross to England.
After traveling some distance the storm overtook us. We were blown far out of our course. The vessel was badly battered. The crew left in a panic, leaving me on board. Just in time the German destroyer came along and took me off. That"s it in a nutsh.e.l.l."
"Yes, and then when you discovered us in our little boat you went and told the captain of the destroyer a lot of nonsense, didn"t you?"
questioned Jimmie in a somewhat aggressive manner. "Why did you do it?"
"I only told him that you had at one time a package that belonged to me.
I wanted the package badly. I thought he would a.s.sist me."
"That wasn"t a very nice way to go about it," declared Jimmie with emphasis. "After searching our baggage twice, and after we had told you how the package was in our kits without our knowledge, also that it had been stolen away from our possession, why didn"t you believe us?"
"There is an old saying that all is fair in love and war!" replied Mackinder. "You know that my country and Germany are at war. As an officer in the British army, it is my duty to do everything possible to a.s.sist my country. I believe that package contains information that my country could use. That is my justification for my acts, and I hope you boys are fair-minded enough to hold no resentment."
"I"m just fair-minded enough to be neutral," declared Jimmie, "if I have to fight for the right to remain that way. I"m just a little sore at you for supposing that four boys who are citizens of a neutral country would be carrying information around for another country at war!"
"I"m sorry you feel that way," said Mackinder. "I a.s.sure you there was nothing personal in my acts. I simply tried to do my best!"
"Well, you did a lot, at that!" returned the lad.
"All right, folks, let"s drop the subject," spoke up Ned. "I feel that the air in here is getting bad. Suppose we go to the surface."
"Right you are," agreed Harry. "Let"s rise and fill the tanks!"
Jimmie, in compliance with this wish, steered the craft upward.