"Did you get any information out of the man in the hospital?" I asked.
"Not a scrap," Hewitt replied. "He was still insensible, and though I saw his clothes, and they told me a good deal about the gentleman's personal habits—which are not dazzlingly noble, to put it mildly—they told me nothing else whatever, except that he had recently been knocked down in the mud, which I knew already. But the cypher has told me something, as I will explain presently."
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
