other simple office
requisites. Two doors led out of it one to the manager's bedroom, the
other to the shed. Thinking that those could wait, Willis settled down
to make an examination of the office.

He ran rapidly though methodically through the papers on the table
without finding anything of interest. All referred to the pit-prop
industry, and seemed to indicate that the business was carried on
efficiently. Next he tackled the desk, picking the lock with his usual
skill. Here also, though he examined everything with meticulous care,
his search was fruitless.

He moved to the cupboards. One was unfastened and contained old ledgers,
account books and the like, none being of any interest. The other
cupboard was locked, and Willis's quick eyes saw that the woodwork round
the keyhole was much scratched, showing that the lock was frequently
used. Again the wire was brought into requisition, and in a moment
the door swung open, revealing to the inspector's astonished gaze--a
telephone.

Considerably puzzled, he looked round to the wall next the door. Yes,
he had not been mistaken; there also was affixed a telephone. He crossed
over to it, and following with his eye the run of the wires, saw that
it was connected to those which approached the shed from across the
railway.

With what, then, did this second instrument communicate? There were no
other wires approaching the shed, nor could he find any connection to
which it could be attached.

He examined the instrument more closely, and then he saw that it was
not of the standard government pattern. It was marked "The A. M. Curtiss
Co., Philadelphia, Pa." It was therefore part of a private installation
and, as such, illegal, as the British Government hold the monopoly for
all telephones in the country. At least it would be illegal if it were
connected up.

But was it? The wires passed through the back of the cupboard into
the wall, and, looking down, Willis saw that one of the wall sheeting
boards, reaching from the cupboard to the floor, had at some time been
taken out and replaced with screws.

To satisfy his curiosity he took out his combination pocket knife, and
deftly removing the screws, pulled the board forward. His surprise was
not lessened when he saw that the wires ran down inside the wall and,
heavily insulated, disappeared into the ground beneath the shed.

"Is it possible that they have a cable?" thought the puzzled man, as he
replaced the loose board an