“And I, too,” I chimed in.
Dorothy said nothing, but as I watched her, I saw the rose of her cheeks growing deeper, and that peculiar change in her eye that showed she had already leaped beyond the reasoning of the others and grasped the answer by intuition. “One question first,” she began, “Mr. Swenton, did the doctor leave the door to the spectroscope room open when he went into his private room?”
“No,” answered Swenton slowly, “he would go into the spectroscope room, lock that door, and then you could hear the inner door open and shut. Sometimes he would not come out again, but I have often heard him come out into the anteroom about three or four minutes after he went in, stay there for a minute or two, then go in again and come out once more. After that he would be shut up there for hours together.”
“That settles it,” cried Dorothy. “I’m sure I know how he opened his secret closet or closets. You remember the insulated wire covering they found, when they came in after the doctor’s death.”
We nodded eagerly.
“That was the winding of an electro-magnet. He attached it to the long flexible cord of that incandescent light socket in the anteroom, took it in, opened his closets, brought it out again, and went back. See if you can find an electro-magnet in the cases or the storeroom, and we’ll open things up.”
Scarcely were the words out of her mouth, before Swenton had hurried to a drawer, and pulled out three small electro-magnets, all of the same size.
“Here are the only ones I know of, in the laboratory,” he exclaimed. “I can connect one of them with the flexible cord in a minute. We shall want more light, though. If one of you gentlemen will get another connector and fix it to a socket, I’ll fit the magnet. You’ll find some connectors for that size socket in the storeroom, I’m sure.”
With four practised hands at work, it was scarce ten minutes before an incandescent stood on the table in the inner room, while we had an electric magnet connected to a long flexible cord which brought current from an incandescent light socket in the next room. Dorothy stood in the centre, once more in command.