I looked at Holmes.

“Can it be true?”

“I should not think so for one minute.”

I was utterly deflated. I felt what the forger’s dupe always feels at first. With all my heart I wanted these lines to be Byron’s own. A cold douche of scepticism was profoundly unwelcome. I had expected my friend’s excitement to turn to enthusiasm. Too late, I saw that his exhilaration was not that of literary discovery but of unmasking a villain. I continued to protest.

“It is entirely convincing.”

“Augustus Howell has a peculiar gift of being entirely convincing. He owes his success to it. Because he has planted this among Aspern’s correspondence from Byron, it will carry all the more conviction in the salerooms of London or New York.”

“How much is in that collection of papers?”

“Enough to kindle a good bonfire.”

My surprise turned to dismay.

“The paper is of the right date-1822?”

“Almost certainly.”

“The ink has rusted over the years?”

“It would appear that it has.”

“It is Byron’s writing.”

“Deceptively like.”

“The handwriting, the ink and the paper are those of seventy years ago. That cannot be Howell. He was not alive seventy years ago.”

“Precisely. Therefore it is a forgery.”

With that he took the letter from my hand and walked to the window again. Holding the page of manuscript horizontally, he tilted it a little this way and that, catching the light on its back and examining the surface with his glass. I felt a certain annoyance at such self-confidence.

I could not tell what he had discovered by scrutinising the surface of the paper. However, he now put it down abruptly, turned to the escritoire and began to pull every drawer clear of its slot. I thought we had already emptied the furniture of all that might be of interest. Now he was looking for scraps. He searched the recesses, as if for some secret compartment. He turned each drawer upside down and shook it, scattering the last fragments of paper, dust and wood-chippings on to the table. Not satisfied with this, he continued to rummage in each of the cavities where the drawers had been. At last he gave a sigh of satisfaction and retrieved a small slip of paper. I could see quite easily what he had found-a receipt from a London ironmonger.

“It behoves us, Watson, to become snappers-up of unconsidered trifles.”

The receipt was stamped by Kinglake & Son, High Holborn, for three shillings and eight pence. Its date was “12 November 1888.” Why should anyone keep a common receipt of this kind for such a length of time and in such apparent secrecy as this? Perhaps, after all, it had not been hidden but had merely fallen from the back of the drawer and been lost behind it. Only Augustus Howell could tell us and he must be presumed dead. Then I saw that there was writing on the back of the receipt.

“1 oz. galls, 1 oz. gum arabick, 1 oz. iron sulphate to oxidise, 6 cloves, 60 grains indigo. Add 30oz. boiling water/stand 12 hours.”

“How soon can we make sense of this?”

“I have already done so. It is a recipe for making iron-gall ink which, I imagine, no one has bothered to do for many years. Logwood and then blue-black replaced it long ago. When I have a reply to my wire, sent to the Vacuum Cleaner Company in St Pancras, we may have a complete explanation.”

“But you have surely not sent such a wire?” “It is remiss of me,” he said impatiently, “I should have known how this would turn out. Trickery-and shoddy trickery into the bargain! We will go to Thomas Cook the courier at once and despatch a cable. Meantime, be good enough to look at the so-called poem of Lord Byron you were reading. Hold it at the window. Let the light fall upon the back of the paper at an angle and tell me what indentations you can make out.”

I stood in the window and held it at various angles, studying it through the magnifying lens.

“It is a little creased here and there, so it should be after seventy years!”

“Look for a pattern.”

“There is a very slight pattern impressed on it.”

“Indeed there is.”

“It appears to be the impression of a grid, a series of horizontal and vertical lines.”

“They suggest, do they not, that the paper has rested for some time on top of such a grid? And that means nothing to you?”

“I can’t say that it does.”

“Then the sooner we reach Messrs Cook, the sooner we shall have an answer.”

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.”