"Sherlock Holmes and the King’s Evil" - читать интересную книгу автора (Thomas Donald)

5

By that evening we had a reply from St Pancras. The so-called Vacuum Cleaner Company had been a novelty a year or two earlier with its new carpet-cleaning device, though the device itself was not new. Holmes, with his insufferable fund of arcane knowledge, assured me that it had been patented in America as early as 1869. The device had originally required two servants to operate it. One worked a pair of bellows to create a vacuum and the other held a long nozzle which sucked up dust.

My friend, intrigued as always by such eccentricities, had quoted to me an article on the subject in the Hardwareman of the previous May. This promised a cleaner operated by a motor instead of bellows. Though I had heard these “vacuum” contraptions spoken of, I had never seen one of them.

As we sat with our coffee at one of Florian’s tables in St Mark’s Square, Holmes offered his explanation.

“The indentations which you observed, Watson, were those created by the paper lying on a wire mesh.”

“Very likely. What has that to do with a vacuum cleaner?”

“To acquire so clear a pattern, the back of the paper must have been supported for some considerable time on a wire screen, held in place by clips or pegs. In addition, the gentle application of a vacuum tube would suck it back against the mesh, for as long was as necessary. Soft paper, such as this, was always made of rags and takes the impression of metal very easily.”

“But that would not alter the apparent age of the paper, surely.”

“Certainly not. What it would alter is the apparent age of the ink.”

“By the use of a vacuum?”

“Cast your mind back to the formula on the ironmonger’s receipt,” said Holmes patiently. It is a prescription for the manufacture of a small amount of iron-gall ink, used by Jeffrey Aspern, Lord Byron and their contemporaries in the 1820s. It was long ago superseded. Therefore, ask yourself why anyone should want iron-gall ink in November 1888.”

“You did not need to send a wire to a vacuum cleaner manufacture in London to learn about black iron-gall ink!”

He looked surprised.

“My dear fellow, of course not. A pair of bellows may produce a vacuum without the assistance of a cleaning device, though with more effort. The wire was merely sent to inquire whether these benefactors of man and womankind had recently supplied one of their excellent machines to Mr Howell of 94 Southampton Row, London West Central.”

“And the answer?”

“They had not.”

“Then you were wrong!”

“Not entirely. They had supplied a machine to that address. However, the customer gave his-or her-name as Mr Aspern.”

He snapped his fingers for the waiter and ordered more coffee.

“Black iron-gall ink sinks very slowly into such paper as this. As it does so, it goes rusty by reason of oxidation. If it remains black then it cannot be of any great antiquity.”

“As any schoolboy might deduce.”

“One moment, if you please! The purpose of a vacuum applied to the back of soft rag paper, long and gently while the ink is still damp, is to draw the fluid more deeply and quickly into the paper, to accelerate the ageing process. All things considered, I believe we may conclude that Byron never intended Don Juan to follow in the footsteps of Thomas Jefferson. However, I think we have followed those of the Bordereau sisters and their forger very closely indeed.”