Part 33 (1/2)

It may be that other motives, besides those connected with George Aspel, induced the man in grey to visit the General Post-Office, but we do not certainly know. It is quite possible that a whole host of subsidiary and incidental cases on hand might have induced him to take up the Post-Office like a huge stone, wherewith to knock down innumerable birds at one and the same throw; we cannot tell. The brain of a detective must be essentially different from the brains of ordinary men. His powers of perception--we might add, of conception, reception, deception, and particularly of interception--are marvellous. They are altogether too high for us. How then can we be expected to explain why it was that, on arriving at the Post-Office, the man in grey, instead of asking eagerly for George Aspel at the Inquiry Office, or the Returned Letter Office, or the _poste restante_, as any sane man would have done, began to put careless and apparently unmeaning questions about little dogs, and to manifest a desire to be shown the chief points of interest in the bas.e.m.e.nt of St. Martin's-le-Grand?

In the gratifying of his desires the man in grey experienced no difficulty. The staff of the Post-Office is unvaryingly polite and obliging to the public. An order was procured, and he soon found himself with a guide traversing the mysterious regions underneath the splendid new building where the great work of postal telegraphy is carried on.

While his conductor led him through the labyrinthine pa.s.sages in which a stranger would infallibly have lost his way, he explained the various objects of interest--especially pointing out the racks where thousands on thousands of old telegrams are kept, for a short time, for reference in case of dispute, and then destroyed. He found the man in grey so intelligent and sympathetic that he quite took a fancy to him.

”Do you happen to remember,” asked the detective, in a quiet way, during a pause in his companion's remarks, ”anything about a mad dog taking refuge in this bas.e.m.e.nt some time ago--a small poodle I think it was-- which disappeared in some mysterious way?”

The conductor had heard a rumour of such an event, but had been ill and off duty at the time, and could give him no details.

”This,” said he, opening a door, ”is the Battery Room, where the electricity is generated for the instruments above.--Allow me to introduce you to the Battery Inspector.”

The man in grey bowed to the Inspector, who was a tall, powerful man, quite fit, apparently, to take charge of a battery of horse artillery if need were.

”A singular place,” remarked the detective, looking sharply round the large room, whose dimensions were partially concealed, however, by the rows of shelving which completely filled it from floor to ceiling.

”Somewhat curious,” a.s.sented the Inspector; ”you see our batteries require a good deal of shelving. All put together, there is in this room about three miles of shelving, completely filled, as you see, with about 22,000 cells or jars. The electricity is generated in these jars.

They contain carbon and zinc plates in a solution of b.i.+.c.hromate of potash and sulphuric acid and water. We fill them up once every two weeks, and renew the plates occasionally. There is a deal of sulphate of copper used up here, sir, in creating electricity--about six tons in the year. Pure copper acc.u.mulates on the plates in the operation, but the zinc wears away.”

The detective expressed real astonishment and interest in all this, and much more that the Inspector told him.

”Poisonous stuff in your jars, I should fancy?” he inquired.

”Rather,” replied the Inspector.

”Does your door ever stand open?” asked the detective.

”Sometimes,” said the other, with a look of slight surprise.

”You never received a visit down here from a mad dog, did you?” asked the man in grey.

”Never!”

”I only ask the question,” continued the other, in a careless tone, ”because I once read in the newspapers of a poodle being chased into the Post-Office and never heard of again. It occurred to me that poison might account for it.--A curious-looking thing here; what is it?”

He had come to a part of the Battery Room where there was a large frame or case of dark wood, the surface of which was covered with innumerable bra.s.s k.n.o.bs or b.u.t.tons, which were coupled together by wires.

”That is our Battery Test-Box,” explained the Inspector. ”There are four thousand wires connected with it--two thousand going to the instruments up-stairs, and two thousand connected with the battery-jars.

When I complete the circuit by connecting any couple of these b.u.t.tons, the influence of the current is at once perceived.”

He took a piece of charcoal, as he spoke, and brought it into contact with two of the k.n.o.bs. The result was to convert the coal instantly into an intense electric light of dazzling beauty. The point of an ordinary lead pencil applied in the same way became equally brilliant.

”That must be a powerful battery,” remarked the detective.

The Inspector smilingly took two handles from a neighbouring shelf and held them out to his visitor.

”Lay hold of these,” he said, ”and you will feel its powers.”

The detective did as directed, and received a shock which caused him to fling down the handles with great prompt.i.tude and violence. He was too self-possessed a man, however, to seem put out.

”Strong!” he said, with a short laugh; ”remarkably strong and effective.”

”Yes,” a.s.sented the Inspector, ”it _is_ pretty powerful, and it requires to be so, for it does heavy work and travels a considerable distance.