"Miss Winthrop!" exclaimed Grayson, "I can't believe it!"

"Read the paper I gave you, Mr. Grayson," directed The Thinking Machine coldly. "Perhaps that will enlighten her."

The financier opened the sheet, which had remained folded in his hand, and glanced at what was written there. Slowly he read it aloud: "PEABODY--Sell ten thousand shares L. & W. at 97. MCCRACKEN Co.--Sell ten thousand shares L. & W. at 97." He read on down the list, bewildered. Then gradually, as he realized the import of what he read, there came a hardening of the lines about his mouth.

"I understand, Miss Winthrop," he said at last. "This is the substance of the orders I dictated, and in some way you made them known to persons for whom they were not intended. I don't know how you did it, of course; but I understand that you did do it, so----" He stepped to the door and opened it with grave courtesy. "You may go now."

Miss Winthrop made no plea--merely bowed and went out. Grayson stood staring after her for a moment, then turned to The Thinking Machine and motioned him to a chair. "What happened?" he asked briskly.

"Miss Winthrop is a tremendously clever woman," replied The Thinking Machine. "She neglected to tell you, however, that besides being a stenographer and typist she is also a telegraph operator. She is so expert in each of her lines that she combined the two, if I may say it that way. In other words, in writing on the typewriter, she was clever enough to be able to _give the click of the machine the patterns in the Morse telegraphic code_--so that another telegraph operator at the other end of the 'phone could hear her machine and translate the clicks into words."

Grayson sat staring at him incredulously. "I still don't understand," he said finally.

The Thinking Machine rose and went to Miss Winthrop's desk. "Here is an extension telephone with the receiver on the hook. It happens that the little silver box which you gave Miss Winthrop is just tall enough to lift this receiver clear of the hook, and the minute the receiver is off the hook the line is open. When you were at your desk and she was here, you couldn't see this telephone; therefore it was a simple matter for her to lift the receiver, and place the silver box underneath, thus holding the line open permanently. That being true, the sound of the typewriter--_the striking of the keys_--would go over the open wire to whoever was listening at the other end. Then, if the striking of the keys typed out your letters and, by their frequency and pauses, simultaneously tapped out telegraphic code, an outside operator could read your letters at the same moment they were being written. That is all. It required extreme concentration on Miss Winthrop's part to type accurately in Morse rhythms."

"Oh, I see!" exclaimed Grayson.

"When I knew that the leak in your office was not in the usual way,"

continued The Thinking Machine, "I looked for the unusual. There is nothing very mysterious about it now--it was merely clever."

"Clever!" repeated Grayson, and his jaws snapped. "It is more than that.

Why, it's criminal! She should be prosecuted."

"I shouldn't advise that, Mr. Grayson," returned the scientist coldly.

"If it is honest--merely business--to juggle stocks as you told me you did, this is no more dishonest. And besides, remember that Miss Winthrop is backed by the people who have made millions out of you, and--well, I wouldn't prosecute. It is betrayal of trust, certainly; but--" He rose as if that were all, and started toward the door. "I would advise you, however, to discharge the person who operates your switchboard."

"Was she in the scheme, too?" demanded Grayson. He rushed out of the private office into the main office. At the door he met a clerk coming in.

"Where is Miss Mitch.e.l.l?" demanded the financier hotly.

"I was just coming to tell you that she went out with Miss Winthrop just now without giving any explanation," replied the clerk.

"Good day, Mr. Grayson," said The Thinking Machine.

The financier nodded his thanks, then stalked back into his room.

In the course of time The Thinking Machine received a check for ten thousand dollars, signed, "J. Morgan Grayson." He glared at it for a little while, then indorsed it in a crabbed hand, _Pay to the Trustees'

Home for Crippled Children_, and sent Martha, his housekeeper, out to mail it.