“The vogue for English notepaper on the Continent has led French and German mills to produce so-called ‘English writing paper’,” he added. “And if I am not mistaken this is a specimen.”

For nearly a week Smeaton prosecuted his inquiries of stationers, wholesale and retail, in all parts of the metropolis, taking with him always the tracing of the watermark. He did not carry the letter, for obvious reasons.

One day at a small retail stationer’s in the Tottenham Court Road, when he showed the tracing to the elderly shopkeeper, the man exclaimed:

“Oh, yes! I’ve seen that before. It’s foreign. When I was an assistant at Grimmel and Grice’s in Bond Street, Mr Grice bought a quantity of it from Paris because of its unusual colour and texture. It was quite in vogue for a time, and it could only be obtained from us.”

“Then all of this particular paper came from Grimmel and Grice’s?”

“Certainly, sir, I recollect the ‘Westford Mill’ well. We supplied it to half the aristocracy of London.”

Smeaton, much pleased with his discovery, took a taxi to Bond Street, and entering the fashionable stationers’ addressed himself to the first person he saw, a young man of about twenty-five.

“Do you make this paper nowadays?” he asked.

The shopman examined it, and shook his head. “No, sir, that paper has not been sold here since I’ve been in the business.”

“And how long would that be?”