By this time we had reached the high floor in which the offices stood, and Mr. Bell, all wonder and pale agitation, unlocked the outer door, and turned on the electric light.
"Now," cried Hewitt, "show me your ventilators!"
There were some, it seemed, in the top panes of the windows, but these were not what Hewitt wanted. There were others in the form of upright chambers or flues, made of metal, and painted the same colour as the walls about them. They rose from the floor in corners and wall angles, and could be shut or opened by means of lids over their upper ends. These were more to Hewitt's mind, and he went about from one to another, groping under the lids, and poking down into the flues with a walking-stick. There was a wire-grating, or diaphragm, it seemed, in each of them, two or three feet down, and we could hear the end of the stick raking on this at each investigation. One after another of these ventilators Hewitt examined, till he had examined them all, in outer and inner rooms, without result; and I could see that he was disappointed.
"There must be another somewhere," he said, and hunted afresh.
But plainly he had tried them all, and now he could do no more than try them all again, with as little result.
"It is a ventilator," he said, positively. "Unless——" he broke off thoughtfully and stood silent for a few moments. "Ah! of course!" he resumed presently. "We'll send for the housekeeper and a candle. Which is the nearest empty office—the nearest office to let? Is there one on this floor?"
"I think not," Mr. Bell answered. "But there's one on the floor below, just opposite the lift—I see the bill on the door every day as I come up."
"We'll try that, then. I'll rake out every ventilator in this palatial edifice before I'll call myself beaten. Come, call the housekeeper. Is there a speaking tube? Tell him to bring a light."
The housekeeper came, wonderingly, with a watch-man's oil-lantern, and we all went to the floor below. Opposite the lift was a glass door from which a bill had recently been torn.
"Why, it's let!" said Mr. Bell.