It had seemed to Sidney and Raymond that they had attained to the height of ease when they boarded the train at Tiflis after their tremendous tramp and were transported without effort on their part. But when the Princess Mary drew away from the pier at Batum and started westward across the Black Sea, the travelers felt that they were then enjoying sublimated luxury.

The great sea lay rippling gently under a peaceful autumn sky, and the little steamer drove steadily ahead on a level keel. It was as though they were navigating a small lake. Captain Foster’s cargo consisted wholly of oil, so that he put in at no ports, but made a straight run from Batum to Venice.

As the Princess Mary used oil for fuel, her crew was made up chiefly of engineers. There were only four sailors, one of whom was the captain’s first officer, and a cook. The mate, Mr. Wright, sat at the captain’s table, so with the boys there was a nice little party of four.

Captain Foster had a great fund of stories gathered during a sea life of forty years, and he remembered and was willing to relate them all. And as the voyage was very uneventful, the captain’s time was largely unoccupied, and he employed much of it in story-telling. So the boys had not a dull moment.

After two days of such sailing the Princess Mary entered the Bosporus. It had been Captain Foster’s custom to stop at Constantinople, but there had lately been so many rumors that Turkey was about to join Germany in the war that he decided to make no stop on that voyage. The ship, therefore, was headed to pass directly through, and the boys thought that they would see the interesting foreign sights only from a distance. There was the great city of Constantinople on one side, and the beautiful heights of Scutari on the other, both of which places they would have loved to visit. Then, as they were passing the entrance to the harbor of the Golden Horn, a launch flying the Turkish flag signaled them to stop.

In obedience to the summons Captain Foster lay to, and they were boarded by a Turkish officer who demanded their clearance papers. After he had examined the papers he went below with Captain Foster to inspect the cargo.

Sidney and Raymond waited on deck in great anxiety. They could not face with equanimity the possibility of being detained at Constantinople. The narrow straits into which they had entered seemed to them like the door through which they would pass for home, and to have that door close and shut them out was too dreadful to contemplate.

“Sid,” said Raymond, as they waited in suspense for the return on deck of the Turkish officer, “if we are stopped here I shall escape in some way and swim across to the other side. If Byron could do that with his club feet I am sure I can.”

“But Byron, you know, swam across the other strait, not this one, and that’s probably narrower.”

“I don’t believe it’s any narrower than it is here; why, this is no width at all.”

“Well, if you got across you would still be in Turkey.”

“Yes, but it would be in the country, and not in a big city.”

“It would be in the country if you could land outside of Scutari, but that looks like a pretty big place from here.” And Sidney gazed across at the heights on the other side which were covered with buildings.

“I don’t care what there is over there,” declared Raymond; “there’s one thing sure, I’m not going to stay in Constantinople.”

“I don’t believe they’ll stop us,” said Sidney; “they’ll be careful how they stop Americans. But we’ll soon know, for here comes that Turk.”

The officer approached and looked at the boys, not unkindly.

“Where are you boys started for?” he asked in excellent English.

“We are going back to New York,” replied Sidney.

“Do you live in New York?”

“No; we live in Texas.”

“Texas; that’s a big State. Let’s see your passport.”

Sidney presented that paper to the officer, who read it hastily.

“H—m,” he said, “that’s a curious passport, but I think it will do. We don’t want to stop boys, anyway.” Then turning to Captain Foster, “Your papers are all right, captain.” And he added significantly, as he went down the side, “I think there is going to be a storm; don’t let it catch you in the Straits, or you might be wrecked.”

As soon as the Turkish officer had left the ship, Captain Foster sprang to the signal-button for the engine-room and rang full speed ahead. The Princess Mary’s screws churned the water furiously, and she was soon throwing the spray back from her bows. But the captain did not appear to be satisfied; he told the man at the wheel to keep her well in the middle of the stream, and rang for greater speed. In obedience to his demands dense black smoke poured from the funnel, and the little vessel ploughed through the water faster than the boys had supposed could be possible.

“You see the Princess Mary is good for something, if she is old,” said Captain Foster proudly as he returned to the boys.

“She can’t go too fast to suit me, captain,” said Sidney, watching with pleasure the shores as they glided past.

“Nor me either,” said the captain. “That officer is an old friend of mine, and he meant for me to sit up and take notice when he gave me that warning.”

“About the storm?” asked Raymond. “I wondered what he meant. It doesn’t look now as though it would ever storm.”

“He meant something worse than a windstorm,” said the captain. “But if I can have until to-morrow morning, they may do what they please.”

“Do you think Turkey is going into the war?” asked Sidney.

“I think that’s what they’re getting ready for,” replied the captain.

“Which side will they join?”

“Well, it won’t be England; I’m sure of that. They would just love to kick up a fuss in Egypt.”

Captain Foster kept close watch of the Princess Mary’s speed, and did not allow the engines to subside in the least. So long as they were threading the narrow Strait of the Bosporus, the boys were kept fully occupied in watching the various interesting sights on either side, and the numerous shipping which they met.

After a time, however, the ship drew out into the Sea of Marmora, and then there was less of interest to be seen. The captain, too, appeared distrait, and was not so good company as he had been while they were traversing the Black Sea. So the boys felt rather dull, and when night came they went to bed early.

In the morning when the boys looked out of their porthole of a window, they thought the ship must be still in the Sea of Marmora, for there was only water to be seen on either side.

“I wish this old tub could go faster,” said Raymond grumblingly. “We’ll never get to Venice at this rate.”

“She seems to be making good speed,” said Sidney, as he watched the water surge past the side of the boat. “I don’t understand why we aren’t farther along; perhaps they were obliged to lie to for some reason in the night.”

The boys dressed rapidly and went out to hunt Captain Foster, whom they found pacing the deck and looking very happy.

“Good-morning, captain,” called out the boys; and Sidney added,—

“When shall we reach the Dardanelles?”

“Why, bless you,” replied the captain, beaming on the boys, “we passed the Straits last night, and we’re well out in the Ægean now. What did you think the Princess Mary had been doing? The old girl is making twenty-two knots.”

“Jiminy, that’s fine!” exclaimed Raymond; “then I suppose we’ll round Cape Matapan to-morrow.”

“Oh, we’re not going to run away down there. We’ll go through the Corinth Canal; that will cut off a whole day.”

“Shall we stop at Athens?” asked Raymond eagerly.

“No, we’ll make no stops, but we’ll be off PirÆus this evening. I shan’t feel really comfortable till we’re tied up at Venice.”

“Well,” said Sidney, “that Turkish storm didn’t materialize.”

“I don’t know whether it did or not,” replied the captain; “but if it did we were beyond it.”

The Princess Mary was too small and unimportant a craft to carry a wireless, and since passing the Dardanelles they had met no vessel within speaking distance. Captain Foster, therefore, had had no opportunity to learn what his friend, the Turkish officer, had meant by the warning he had given. He was, consequently, feeling rather anxious to know if he had passed the danger, whatever it was.

The day wore on uneventfully, and the boys amused themselves as best they might. They went back and forth from the deck, where there was nothing of especial interest, to the engine-room, where there was a good deal. They were left entirely to their own devices, for Captain Foster watched the horizon constantly. He knew there was a possibility that they might meet an Austrian cruiser, and in that case he wished to take advantage of whatever chance there might be to escape.

Early in the afternoon the captain called the boys’ attention to the island of Skyros, which showed off on their right, and he told them that before long they would see the mainland of Greece. While they were examining the horizon Raymond thought he saw a tiny line of smoke dead ahead. He called Captain Foster’s attention to it, and the captain brought his binoculars to bear on the spot.

“It’s not a cruiser,” he announced immediately; “it’s a tramp steamer. Do you want to look at her?” And he passed the glasses over to the boys.

“How can you tell that’s not a cruiser?” asked Raymond. “I can’t see anything but a little speck.”

“Well, she’s only got one funnel, for one thing, and she’s too small for another. She doesn’t look like any liner, either. I can’t explain to you exactly how I can tell; I simply know, that’s all.”

As the approaching ship was coming directly toward them, she grew large rapidly. While she was still too small, however, for the boys to distinguish anything about her, even with the glasses, Captain Foster examined her again. He looked intently through the glasses for a few moments, and then declared,—

“It’s the Black Duke, Captain Johnson, from London to Smyrna.”

“Gee! captain,” exclaimed Raymond; “you must have second sight. How do you know what ship that is at this distance?”

“I know her as well as I know the Princess Mary.”

“I couldn’t tell the Princess Mary as far off as that,” declared Raymond.

“Well, I could. When she comes up I’ll speak her and we’ll get the news.”

The two ships rapidly drew together, and laid their courses to pass about one hundred yards apart. When the Black Duke, for such the ship was in fact, was still some three or four hundred yards distant, Captain Foster took the trumpet and shouted,—

“Ahoy! Black Duke.”

“Ahoy! Princess Mary,” came the answer.

“What news of the war?”

“Turkey closed the Dardanelles this morning.”

“Gee!” exclaimed Raymond, “that was a close shave.”

The vessels were now rapidly separating, but Captain Foster launched one more question.

“Is the Adriatic safe?”

“English and French cruisers there, Austrian coast is mined,” was shouted back from the distance.

Captain Foster lowered the trumpet and regarded the departing ship thoughtfully.

“Well,” he said finally, “we escaped that storm, thanks to my Turkish friend. Now if those mines are stationary, we’ll get through, but floating mines I’m afraid of.”

“Do you think Austria would put out floating mines, captain?” asked Sidney.

“Germany has sowed the North Sea with floating mines, and Austria may have done the same thing in the Adriatic. But there is no way we can locate them, so we’ll just have to go straight ahead, and take what comes.”

Having obtained what information he desired, Captain Foster determined to crowd the ship forward at top speed. With Turkey apparently about to join the hostilities and probably on the side of Germany, the quicker they were out of the Ægean the better. While passing through Grecian waters they would be perfectly safe, and in the Adriatic the presence of English and French cruisers would be a great protection, though they would not insure absolute security. The most serious aspect of the whole matter was presented by the mines in the Adriatic. There was no possibility, however, of evading, or minimizing, that danger.

In early evening the Princess Mary entered the Gulf of Ægina, and Captain Foster laid his course directly for the Corinth Canal. Before they arrived at that cut, however, night had closed down. The boys remained on deck to get what impression they might of the country, but after the ship had traversed the canal, and entered the Gulf of Corinth, nothing whatever could be distinguished on either side. When the boys woke rather late the next morning the Princess Mary was passing between the island of Corfu and the mainland.

“What a measly shame!” exclaimed Raymond, when he learned where they were; “here we’ve gone right through the middle of Greece, and we haven’t been able to see one foot of it.”

“Well,” said Sidney, “if we could be set down in New York now, I’d give up all chance of seeing any more foreign countries this trip.”

All that day and all night the Princess Mary steamed steadily northward. At daylight on the following day the ship was far up the Adriatic, opposite the coast of Austria. When the boys went up on deck they found Captain Foster standing in the bow gazing intently out over the water.

“I know I’m silly,” he said when the boys approached, “but I feel like watching every minute for mines, though if they were thick all around us, I shouldn’t know it unless the Princess Mary struck one.”

“It seems to me,” said Sidney, “that mining the sea is a barbarous way to make war.”

“Yes; but making war any way you please is all of a piece.”

“Do you think there is really much danger, captain, that we shall strike a mine?” asked Raymond. “It would seem like being pricked by a needle in a haystack.”

“I don’t know how great the danger is,” replied the captain, “but a good many ships have struck mines and been sunk in the North Sea. I have been thinking that you boys ought to know where the life-preservers are, in case anything does happen. I don’t think there are any in your room, but there are some in the main cabin, underneath the couch. You see the Princess Mary never carries passengers, and we haven’t paid much attention to life-preservers. You’d better get out a couple and bring them up on deck, then you can get into them in a jiffy.”

“Aren’t you going to get one for yourself, captain?” asked Raymond.

“No, I think not. If I had one ready I’d be afraid it would have to be used, and if I don’t get it maybe I shan’t need it. But you boys get them; that will be all right.”

The boys hunted out the life-preservers and took two of them up on deck, placing them by the side of the companionway, where they would be easy to grasp in case of necessity. Then the cook announced breakfast and they went down to the cabin with Captain Foster.

They seated themselves at the table and were seasoning their coffee, when, without warning, the bow of the ship was thrown upward with a terrific shock, accompanied by a muffled roar. The floor of the cabin inclined at a high angle, sloping down toward the stem. For a moment the Princess Mary hung in that terrifying position, while Captain Foster and the boys clung to the table, from which all the dishes had been thrown to the floor. Then the ship settled, not only into place again, but farther than she should, so that the floor inclined the other way.

“Get on deck and into your life-preservers, boys,” said Captain Foster quietly, though with a very pale face; “she won’t last five minutes.”