“No. He used to ask me technical questions,” answered Collison. “You know, I just regarded him as a man who had a natural taste for experimenting with things. This was evidently his hobby. I used to chaff him about it. Still, he was a purposeful man, and by reading and experiment he’d picked up a lot of knowledge.”
“And, I suppose, it’s within the bounds of possibility that he had hit on something of practical value?” suggested Hetherwick.
“Oh, quite within such bounds!—and he may have done,” agreed Collison. “I’ve known of much greater amateurs suddenly discovering something. The question then is—do they know enough to turn their discovery to any practical purpose and account?”
“Evidently, from what he told his granddaughter, Hannaford did think he knew enough,” said Hetherwick. “What I want to find out from a visit to his old laboratory is—what had he discovered?”
“And as you’re not a chemist, nor even a dabbler,” remarked Hollis, with a laugh, “that won’t be easy! You’d better come with us after lunch, Collison.”
“I can give you a couple of hours,” assented Collison. “I’m already curious—especially if any discovery we can make tends to throw light on the mystery of Hannaford’s death. Pity the police haven’t got hold of the man who was with him,” he added, glancing at Hetherwick. “I suppose you could identify him?”
“Unless he’s an absolute adept at disguising himself, yes—positively!” replied Hetherwick. “He was a noticeable man.”
An hour later the three men drove up to a house which stood a little way out of the town, on the edge of the moorland that stretched towards the great range of hills on the west. The house, an old-fashioned, solitary place, was empty, save for a caretaker who had been installed in its back rooms to keep it aired and to show it to possible tenants. The laboratory, a stonewalled, timber-roofed shed at the end of the garden, had never been opened, said the caretaker, since Mr. Hannaford locked it up and left it. But the key was speedily forthcoming, and the three visitors entered and looked round, each with different valuings of what he saw.
The whole place was a wilderness of litter and untidiness. Whatever Hannaford had possessed in the way of laboratory plant and appliances had been removed, and now there was little but rubbish—glass, whole and broken, paper, derelict boxes and crates, odds and ends of wreckage—to look at. But the analytical chemist glanced about him with a knowing eye, examining bottles and boxes, picking up a thing here and another there, and before long he turned to his companions with a laugh, pointing at the same time to a table in a corner which was covered with and dust-lined pots.
“It’s very easy to see what Hannaford was after!” he said. “He’s been trying to evolve a new ink!”
“Ink!” exclaimed Hollis incredulously. “Aren’t there plenty of inks on the market?”
“No end!” agreed Collison with another laugh, and again pointing to the table. “These are specimens of all the better-known ones—British, of course, for no really decent ink is made elsewhere. But even the very best ink, up to now, isn’t perfect. Hannaford perhaps thought, being an amateur, that he could make a better than the known best. Ink!—that’s what he’s been after. A superior, perfectly-fluid, penetrating, permanent, non-corrosive writing-ink—that’s been his notion, a thousand to one! I observe the presence of lots of stuffs that he’s used.”
He showed them various things, explaining their properties and adding some remarks on the history of the manufacture of writing-inks during the last hundred years.
“Taking it altogether,” he concluded, “and in spite of manufacturers’ advertisements and boasting, there isn’t a really absolutely perfect writing-fluid on the market—that I know of, anyway. If Hannaford thought he could make one, and succeeded, well, I’d be glad to have his formula! Money in it!”
“To the extent of a hundred thousand pounds?” asked Hetherwick, remembering what Rhona had told him. “All that?”
“Oh, well!” laughed Collison, “you must remember that inventors are always very sanguine; always apt to see everything through rose-coloured spectacles; invariably prone to exaggerate the merits of their inventions. But if Hannaford, by experiment, really hit on a first-class formula for making a writing-ink superior in all the necessary qualities to its rivals—yes, there’d be a pot of money in it. No doubt of that!”
“I suppose he’d have to take out a patent for his invention?” suggested Hetherwick.
“Oh, to be sure! I should think that was one of his reasons for going to London—to see after it.” assented Collison. He looked round again, and again laughed. “Well,” he said, “I think you know now—you may be confident about it from what I’ve seen here—what Hannaford was after! Ink—just ink!”
Hetherwick accepted this judgment, and when he left Sellithwaite later in the afternoon on his return journey to London, he summed up the results of his visit. They were two. First, he had discovered that the woman of whom Hannaford had spoken in the train was a person who ten years before had been known as Mrs. Whittingham, appeared to be some sort of an adventuress, and, in spite of her restitution to the jeweller whom she had defrauded, was still liable to arrest, conviction, and punishment—if she could be found. Second, he had found out that the precious invention of which Hannaford had spoken so confidently and enthusiastically to his granddaughter and the particulars of which had mysteriously disappeared, related to the manufacture of a new writing-ink, which might, in truth, prove a very valuable commercial asset. So far, so good; he was finding things out. As he ate his dinner in the restaurant car he considered his next steps. But it needed little consideration to resolve on them. He must find out all about the woman whose picture lay in his pocketbook—what she now called herself; where she was; how her photograph came to be reproduced in a newspaper; and, last, but far from least,
