“Where’s dad, Jupe?” asked Jack.

“In his labveroratory, ah reckons,” answered the old colored man.  “Leastways ah ain’t obfustucated any obserwations ob him round der contagiois atmosferics.”

“Come on, Tom,” said Jack.  “Let’s get to dad’s workshop as quick as we can.”

“Why, Jack, you—­you don’t think that anything has happened to him, do you?” asked Tom.

“I don’t know.  He was talking quite cheerfully to me and then, without any warning, he gave a sort of gasp and then everything was silent.”

The next minute the boys entered the workshop of the inventor.

Jack’s worst fears were realized as they gazed at the scene before them.  On the floor, stretched out inanimate before the radio telephone apparatus, lay Mr. Chadwick.  His right hand grasped a letter.

His head lay in a pool of blood, oozing from a cut at the back of his head.

“Dad! dad!  What has happened?” cried Jack, in an agony of alarm, as he fell to his knees at his father’s side.

But Mr. Chadwick did not answer.  The next moment Tom’s shout for help brought everybody about the place running toward the workshop where the alarming discovery had been made.

CHAPTER XVIII.

Into the storm.

“Carry him into the house and get him to bed,” cried Mrs. Bagley, the housekeeper, wringing her hands distractedly.  “Oh dear! poor gentleman, he’s bin a-workin’ too hard, that’s what’s the matter.”

Jupe and Hank Hawkins, the handy man, picked the unconscious man up and carried him to bed, where he was made comfortable.

Jack and Tom made an investigation of the workshop.  At first the cut on Mr. Chadwick’s head had given Jack the impression that he might have been the victim of foul play.

But a brief survey of the place soon dispelled these conclusions.  When he fell, the inventor struck his head against the sharp corner of a table right behind him, Jack concluded, and in this way inflicted the wound.

The letter that his father had been reading when he was stricken still lay on the floor.  Jack picked it up.  It was from the brokers in New York, the same missive Mr. Chadwick had referred to over the radio ’phone just before the silence that so alarmed Jack.

Glancing over it Jack’s eyes widened.  He perceived at once that the cause of his father’s sudden attack no doubt lay in the shock he had received when he opened the envelope.  The letter was curt and to the point.

“Your securities wiped out in panic,” it said.  “Wire us and advise what to do.”

That was all, but it was enough.  Jack knew that most of his father’s money was invested with the firm that had written the letter, and now they had been wiped out in a money panic.  Jack had no idea how much of his father’s fortune was affected, but it was evident from Mr. Chadwick’s collapse that he had been dealt a heavy blow.