Yet at no time was I one of the circle about me. At no time was I anything more than a spectator of their ever-shifting and ever-mystifying dramas. And this not unnatural secretiveness on their part, combined with a not unnatural curiosity of my own, finally compelled me to a method of espionage in which I grew to take some little pride.
This method, for all its ingenuity, was simple enough to any one of even ordinary scientific attainments. When I found, for example, that the more select of those underworld conferences invariably took place in one of that tier of wood-partitioned drinking-rooms which lined the café's east side, I perceived that if I could not invade those rooms in body I might at least be there in another form. So with the help of my friend Durkin, the reformed wire-tapper, I acquired a piece of machinery for the projection of the spirit into unwelcome corners.
This instrument, in fact, was little more than an enlargement of the ordinary telephone transmitter. It was made by attaching to an oblong of glass, constituting of course, an insulated base, two carbon supports, with cavities, and four cross-pieces, also of carbon, with pointed ends, fitting loosely into the cavities placed along the side of the two supports. The result was, this carbon being what electricians call "a high resistance" and the loose contact-points where the laterals rested making resistance still higher, that all vibration, however minute, jarred the points against their supports and varied resistance in proportion to the vibration itself. This, of course, produced a changing current in the "primary" of the induction coil, and was in turn reproduced, greatly magnified, in the "secondary" where with the help of a small watch-case receiver it could be easily heard.
In other words, I acquired a mechanical sound-magnifier, a microphone, an instrument, of late called the dictaphone, which translates the lightest tap of a pencil-end into something which reached the ear with the force of a hammer-blow. And the whole thing, battery, coil, insulated wire, carbon bars and glass base, could be carried in its leather case or thrust under my coat as easily as a folded opera hat.
It was equally easy, I found, to let it hang flat against the side wall of that rancid little chambre particuliere which stood next to the room where most of those star-chamber conspiracies seemed to take place. My method of adjusting the microphone was quite simple.
From the painted wooden partition I lifted down the gilt-framed picture of a bacchanalian lady whose semi-nudity disseminated the virtues of a champagne which I knew to be made from the refuse of the humble apple-evaporator. At the top-most edge of the square of dust where this picture had stood, I carefully screwed two L-hooks and on these hooks hung my microphone-base. Then I rehung the picture, leaving it there to screen my apparatus. My cloth-covered wires, which ran from this picture to the back of the worn leather couch against the wall, I very nicely concealed by pinning close under a stretch of gas pipe and poking in under the edge of the tattered brown linoleum.
Yet it was only on the third evening of my mildly exhilarating occupation in that stuffy little camera obscura that certain things occurred to rob my espionage of its impersonal and half-hearted excitement. I had ordered a bottle of Chianti and gone into that room to all intents and purposes a diffident and maundering bon-vivant looking for nothing more than a quiet corner wherein to doze.
Yet for one long hour I had sat in that secret auditorium, with my watch-case receiver at my ear, while a garrulous quartette of strike-breakers enlarged on the beatitude of beating up a "cop" who had ill-used one of their number.
It must have been a full half hour after they had gone before I again lifted the phone to my ear. What I heard this time was another man's voice, alert, eager, a little high-pitched with excitement.
"I tell you, Chuck," this thin eager voice was declaring, "the thing's a pipe! I got it worked out like a game o' checkers. But Redney 'nd me can't do a thing unless you stake us to a boat and a batch o' tools!"