"But have you any actual proof of this?" he inquired.
As he spoke the door opened, and there entered a pretty dark-haired girl of twenty-two, wearing a light skirt and a pale pink evening blouse.
"Oh, dad!" she exclaimed, halting suddenly, "I'm sorry I didn't know you had a visitor."
"I shan't be a moment, Nella dear," the curious-looking old man said, and after a quick, inquisitive glance at me the girl withdrew.
"Well," exclaimed the Professor, with a smile, "I'm really very obliged to you for troubling to come here to warn me, but I think, my dear sir, that warnings are quite unnecessary. I haven't the slightest fear that any attempt will ever be made to secure my secret"; and he rose impatiently.
"Very well," I replied, shrugging my shoulders. "I have warned you, Professor Emden. The Government will not admit the presence of spies amongst us, and for that reason we are now collecting indisputable evidence."
"Ah!" he laughed, "and you want me to help you, eh? Well, sir, I don't believe in a word of this scare--so I must decline that honour."
"And you will take no unusual precaution to keep the truth out of the hands of our enemies, eh?"
"I leave it to Joynson's of Sheffield," he said. "They've paid me a large sum down and a royalty for the secret of my process, and it is scarcely likely that they'll allow it to fall into other hands, is it?"
"They will not, but you, a private individual, may," I said.
"I think not," he laughed, and a moment later I descended the stairs, passing his pretty daughter Nella on the way out.
That night I called on Ray at Bruton Street, but he was out at the theatre with Vera. At half-past eleven they called as they went back to the girl's aunt's, and as they sat before the fire, Vera with her opera-cloak thrown back revealing a pretty pale blue corsage a trifle _décolleté_, I reported the non-success of my mission.
"He's a pig-headed old ass!" I declared. "One of millions of others in England. They close their eyes to the dangers of this horde of spies among us, and will only open them when the Germans come marching up the street and billet themselves in their houses. But he's a strange man, Ray, a very strange man," I added.
"You're right, Mr. Jacox," the girl declared. "Instead of teaching boys how to scout and instructing young men in the use of popguns, we should strike first at the root of all things. Cut off the source of this secret information which daily goes across the North Sea. Such hidebound patriots as the Professor are a peril to the nation!"