As he stood thinking, half consciously he tried the cover of the box. To his surprise it gave. He opened it. And the box almost fell from his hands.
It still contained the money! And apparently untouched!
But in a moment Jack thought he understood. Smith, or whoever it was, had left it as a clever means of saving themselves from the worst in the event of being found out, intending to return for it if the excitement blew safely over.
Then why not wait and catch them at it?
Good. But how?
Jack’s inventive genius soon furnished the answer. “That’s it! Great!” he said to himself delightedly. “I’ll get down and do it early in the morning. And now I’ll stick this back in the hole and fix the bricks up again.”
Seven o’clock the following morning found Jack carrying out his plan. First conveying to the cellar from the battery room two gravity-jars, he placed them in a dark corner behind the furnace. Next, finding an old lightning-arrester, he opened up the hiding-place, and arranged the arrester beneath the cash-box in such a way that on the box being moved the arrester arm would be released, fly back, and make a contact. Then, having carefully closed the opening, he procured some fine insulated wire, and proceeded to make up his circuit: From the arrester, out beneath the bricks, around the furnace, to the battery; up the wall, and through the floor by the steam-pipes into the business office; and, running up-stairs and procuring a step-ladder, on up the office wall, through the next floor, into the operating room. And there a few minutes later he had connected the wires to a call-bell on a ledge immediately behind the table at which he worked. And the alarm was complete.
Although Jack knew that the clerk next door returned from his dinner a half hour earlier than the others in the express office, he had little expectation of Smith visiting the cash-box at that time. Nevertheless, as the noon-hour drew near he found himself watching the alarm-bell with growing excitement.
“There might be just a chance of Smith visiting the box,” he told himself, “just to learn whether I had—”
From behind him came a sharp “zip, zip,” then a whirr. With a bound Jack was on his feet and rushing for the door. Down the stairs he went, three steps at a time, and into the manager’s private office.