They kept watch at turns during the night, but nothing unusual occurred, and Percival said to Jack with a laugh:

"Our pickets did good service last night, but I wonder if they will be on to-night?"

"We can't tell. The doctor has said nothing, and we don't know if he has done this on his own initiative or because of what he may have heard."

"Well, it is evident that we boys won't be called on to act as guards, and I am glad of it, for if there is anything I do not like it is having to parade up and down in the cold and dark for nothing when I might better be in my bed."

"I can sympathize with you," said Jack.

During the morning Percival saw Bucephalus alone, and said to him, holding one hand behind his back:

"Was it your idea to keep guard last night, Buck?"

"No, sah, Ah was ready to do it, 'cause young Mistah Smith done offah me a dollah fo' de service, but de doctah done intimate dat he t'ought it would be judicious."

"How did the doctor know that we needed a picket?"

"Ah donno, sah, Ah reckon he thought it was acco'din to military etiquette, sah. It am de custom in military camps to set a picket an' all presume he argued from dose premises, sah."

"Then you did not tell him of what occurred the other night?"

"No, sah, Ah didn't communicate nothing, sah. Mebbe it was one of de odah fellahs."

"You are sure that you said nothing?"

"Yas'r, Ah is suttinly shuah dat Ah made no communication whatsoeber regardin' de events of de perceedin' night, sah. Ah was suttin dat young Mistah Smith would keep his wo'd abo 't de extra remuneration, sah, an' Ah didn't wanter prejudice de situation, sah."

"Oh, I see," laughed Dick. "Then Dr. Wise acted on his own initiative from information received elsewhere, is that it?"

Bucephalus scratched his woolly head, and answered:

"Ah donno abo't de inflammation an' de oder misery, sah. Am it so bad as all dat, sah?"

"I mean that he did it on his own account, and not because of anything that you may have told him."

"All reckon so, sah," said Bucephalus, greatly relieved. "Ah done told him nothin', an' Ah don' guess nobody else told him."

Percival went away laughing, but tossed the coin he held in his hand to Bucephalus, who caught it deftly and grinned.

"The doctor either found it out himself or some one has told him,"

he said to himself, "but it is clear that he knows about it. He would not set a guard on the camp unless he had a good reason, for strangers do not visit us, and the Riverton police probably have orders to keep their eyes on the place."

Seeing Jack shortly afterward, Dick told his friend what he had learned and added:

"The Riverton police would simply keep a watch against strangers, but the doctor evidently thinks that some of our own Hilltoppers need watching, and he has, therefore, taken this means of doing it.

"I am sorry that he has had to," said Jack, "but after all the doctor appears to be living up to his name. We must find out who the fellows were, Dick, for the sake of the decent boys of the Academy, not that I care so much about my boat."

"We will do it, Jack," said Percival shortly.

CHAPTER V

AN ALARM IN THE NIGHT

The day passed as usual, Percival saying no more about trying to discover the miscreants who had sought to injure Jack's boat, and Jack being too busy to think of it.

That evening they had visitors from a fine house in the neighborhood, the owner of which, quite a wealthy man, complimented Dr. Wise on the good character of the boys, adding in rather a pompous manner:

"I must say, Doctor, that since you have been encamped on the river I have had nothing to complain of on account of your boys. Most boarding school boys are inclined to be mischievous, and to cause a good deal of annoyance to persons living in the neighborhood, but I must say-----"

"The Academy is not an ordinary boarding school, Mr. Vanderdonk, and the character of the young gentlemen in my charge-----"

"I beg your pardon, sir, but your pronunciation of my name shows that you do not quite understand the way it is divided. It is Van der Donk, with an equal emphasis upon each syllable, not Vanderdonk, with the accent on the first. I am most particular about the pronunciation of the name, which is that of one of the earliest settlers of the Hudson valley, and a very distinguished one, I may say. I am exceedingly proud of my origin, pardonably so, perhaps, but still most proud."

"Dr. Wise does not care anything about genealogy, Father," spoke up Miss Margaret, daughter of the proud descendant of the Van der Donks, "and you should not have spoken of the Academy boys as boarding school boys. They attend a military Academy, the fame of which is as great as that of your ancestors. Everybody along the Hudson valley knows the Hilltop boys and any young gentleman might be proud to be one of them."

Miss Margaret was a very pretty girl, a bit spoiled, perhaps, but the idol of her father and the puzzle of her mother, who wished her to be a young lady of society, and was greatly grieved because she preferred doing something by which she could earn her living if necessary.

"Far from saying anything against the character of the Hilltop boys, my dear," said the father, "I must say that I find them a very fine set of young gentlemen. Why, we have not had our lawn tramped over by them, nor our fruit trees pilfered, nor have we suffered from any annoyances which boarding school boys are prone to commit upon neighbors. I am really-----"

"Why, Father, you speak as if the boys were from a primary school, and had not learned the first rules of manners," laughed Margaret gaily. What do you expect, Father dear? That the boys shall be young ruffians?"

"Well, perhaps not that, my dear," replied Van der Donk loftily, "but the city boys who come out here-----"

"The poor fellows never saw a tree before in their lives, and they just wanted to make love to them," interrupted Margaret, again laughing in the gayest fashion. "Could you blame the poor unfortunates for wanting to shin up them and pick peaches and apples and everything else? The only fruit they had ever seen was stale and on city stands, and when they saw the real article it was no wonder that they wanted it. You could not blame them."

Then Miss Margaret admired the boats, and accepted Jack's invitation to take her out on the river, her father and mother accompanying her, of course, and Percival going along to talk to the old folks and give Jack a chance to devote himself to the young lady.

Jack was quite taken with the girl whom he considered very natural and a good deal better company than her father who was forever trying to impress everybody with the renown of the Van der Donks, past and present, and after the company had gone Dick said to him:

"Very pretty girl, Miss Margaret, and has lots of sense, but what a tiresome old bore that father of hers is."

"Yes, indeed," laughed Jack, "but there and many persons who parade their blue blood and fine ancestry before the world just as much as he does. What is he, pork merchant or something like that?"

"Pretty good, Jack," said Percival with a grin. "He was a butcher at one time, but don't mention it if you don't want to earn his everlasting scorn. It is never spoken of. He is one of the wealthiest men along the river, and employs a man to do nothing but cut off his stock coupons. They may invite us to the house, although they are a very exclusive sort and are supposed to associate only with millionaires, and the descendants of the oldest and best families."

"The girl does not seem to have any of that nonsense," said Jack, "and she is really very pleasant company. By the way," with a smile, "she did invite me to the house, but I guess you did not hear it."

"Well, well, you are coming on, Jack!" exclaimed Dick. "Of course she would invite you. Why not?"

"And she asked me to bring you, Dick," with another chuckle. "That is all right, too, isn't it?"

"Why, of course!" and Dick grinned again. "We will go as soon as we can, Jack."

The visit to the fine house back of the river was made sooner than the boys anticipated, and in a most unexpected and unusual fashion.