don't know whether to let you go or not. Why, you'd be lost inside of ten minutes in New York, and instead of being a help to the police, you'd keep them busy hunting for you. I don't know about this. Wait till your father gets home and we'll talk it over."

"But, mother," protested Henry, "I can't wait. And we've got to go. The Chief of the Radio Service has asked for our help. That means the government wants us. If it wants us, it must need us. And we've just got to go."

"Humph!" said Mrs. Harper.

"And besides," added Henry, reading the signs in his mother's face, "Dr. Hardy is to be in New York with us, so we can't get into trouble."

"Well, that alters the case," said Mrs. Harper. "With Dr. Hardy to look after you, I reckon you can't go very far astray."

"Then we can go, mother?"

"I suppose so. I know your father thinks every one of us should do everything he possibly can to help win this war. But it gets me to know what you youngsters can do that will be of any use. Still, I guess the government wouldn't have sent for you if it didn't want you, and I won't stand in the road of the government."

"Hurrah!" shouted Henry. "Then I'm off to tell the others." And he darted out of the yard and was away like an arrow.

CHAPTER III

THE WIRELESS PATROL PREPARES FOR ACTION

At top speed Henry tore down the street.

Half a block from his home he passed a schoolmate.

"Hey! What's your hurry?" the latter called out, as Henry dashed past him.

"Wireless patrol ordered out!" Henry shouted over his shoulder, as he darted on down the street.

"Wait a minute!" called the other lad.

"Can't," cried Henry. "Got to get the patrol together to go on a spy hunt."

At the words "spy hunt" the other boy leaped forward and ran after Henry at top speed. "What's up?" he asked enviously, as he overtook Henry and raced along beside him. For the lad did not belong to the wireless patrol.

"Ordered to New York by the government," panted Henry, "to hunt for German spies."

The announcement had all the effect Henry intended it to have. For a full half minute his companion said never a word, but ran mutely beside him, his eyes fastened incredulously on Henry. Then, "Gee whiz!" he said. "You're not really goin' to New York!"

"Sure thing," panted Henry. "Just got a telegram from Washington."

That was too much for Henry's companion. "Gee whiz!" he said again. "I wish I belonged to the wireless patrol."

Henry looked at him sympathetically, half sorry that he had said what he had. "Maybe you will some day," he replied. "Good-bye."

They had reached the home of wee Willie Brown. Henry stopped abruptly and turned in at the open gate. He mounted the steps and rang the bell. Mrs. Brown opened the door.

"Is Willie—at home—Mrs. Brown?" he asked, all out of breath.

"Yes, Henry," replied Mrs. Brown. "You'll find him up in his room."

"Is he busy?"

"Oh! He's tinkering with his wireless, as usual," said Mrs. Brown. "But he's always glad to see you, Henry."

"He will be this time, I'm sure," said Henry. "The wireless patrol is ordered out on a spy hunt."

"What! Not again?" queried Mrs. Brown, in astonishment. "Where are you going this time?"

"To New York," rejoined Henry, and his voice plainly showed his exultation.

"Tell me more about it." Mrs. Brown was at once all seriousness.

Henry turned away from the stair door and explained the situation to Mrs. Brown, who was very sober. But when Henry said that Dr. Hardy had asked the boys to come and that he would himself be with them in New York, the serious look vanished from Mrs. Brown's face. "That's all right, then," she said. "If Dr. Hardy wants you and is to be there to look after you, it is all right. I am glad Willie has the opportunity to go. He has never been in a really big city."

Henry went on up to Willie's room and broke the news to him. And the sounds that came down to Mrs. Brown made her laugh heartily. But it was a laugh of sympathy. She remembered that she had once been young herself. Presently the racket up-stairs subsided. Then came the clatter of noisy and eager feet on the stairs. And a moment later Henry and Willie skipped out of the door, tore through the gate, and went racing up the street toward Roy Mercer's house.

But Roy was not at home. He was, as Henry had suspected he would be, at work in the garage where he had been employed during the school vacation. But Henry thought it would be well to secure permission from Mrs. Mercer for Roy to take the trip to New York, for she was inclined to be rather strict with Roy.

"Captain Hardy has just sent me a request for four of the boys of the wireless patrol to come to New York," said Henry, diplomatically, "and Roy is one of the four he wants. We came to see if he may go."

Mrs. Mercer looked at Henry keenly. "What are you going to do in New York," she demanded, "and who's to pay the bills?"

"I don't know exactly what we're to do," said Henry, "but we're to help the wireless service. I think they want us to listen in and pick up low-length messages that the high-powered government stations don't get. The government will pay our expenses."

"Humph!" said Mrs. Mercer. Then she was silent a moment in thought. "When does Dr. Hardy want you to go?"

"He wants us to meet him in New York at two o'clock Friday afternoon. That means we should have to leave here on the early morning train Friday."

"I don't know about this," said Mrs. Mercer. "All play and no work is just as bad for a boy as no play and all work. And Roy has done nothing but play all summer. He has been at that camp of yours ever since school closed. And besides, he is earning three dollars a week working at the garage."

Henry had feared that Mrs. Mercer would object to Roy's going. Roy's father had been sick and unable to work for some weeks, and Henry knew that the three dollars Roy earned each week were badly needed in the Mercer home.

"I think that the government will pay Roy more than he earns now," explained Henry. "And I hope that you will let him go because Captain Hardy wants only certain boys and Roy is one of them. He is very necessary to the success of our work."

"I'll see what Roy's father says," was the reply, and Mrs. Mercer vanished within the house.

Meantime Henry and Willie stood on the porch hardly daring to speak to one another, so fearful were they that Roy might not be allowed to go. When Mrs. Mercer suddenly appeared again and announced briefly that Roy could go, they thanked her, and as soon as they could get around a corner, they gave vent to their feelings in a loud whoop.

Lew Heinsling was picked up a few minutes later, with no objection on the part of his parents, and the three boys raced to the garage, where they imparted the news to Roy.

School, which normally should already have been in session, had been kept from opening by an epidemic of measles; and no one knew when it would convene. But there was no apparent chance of an early opening, for the epidemic was then at its worst. There was no obstacle now in the way of the four boys. Roy got his employer's permission to leave the garage for an hour, and the four boys hurried to the wireless patrol headquarters in Henry's shop, to discuss the adventure that lay before them.

That night the entire patrol assembled in the little workshop and those who were not to go enviously discussed the coming adventure with the four who had been summoned to duty. For no one in the patrol doubted that the expedition would end in adventure and excitement, to say nothing of the delights of a trip to the nation's metropolis. Their common experience in running down the dynamiters at the Elk City reservoir gave these boys the certainty that both adventure and danger lay ahead of their four lucky fellows. But could they have known how