Thorndyke, however, was in no mood for tea and gossip. He had got a first-class clue—a piece of really conclusive evidence. How conclusive it was and how far its conclusiveness went, he could not tell at present; and he was eager to get to work on the assay of this specimen in an evidential sense—to see exactly what was the amount and kind of evidence that the sea had cast up on the shore of Morte Hoe. He therefore excused himself, and having bidden Phillip adieu, he strode out into Chancery Lane and bore south towards the Temple.
On entering his chambers he discovered his assistant, Polton, in the act of transferring boiling water from a copper kettle to a small silver teapot; whereby he was able to infer that his approach had been observed by the said Polton from his lookout in the laboratory above. The two men, master and man, exchanged friendly greetings and Thorndyke then observed:
“I have got a job to do later on, Polton, when I have finished up the evening’s work. I shall want to grind some small sections of a mineral that I wish to identify. Would you put out one or two small hones and the other things that I shall need?”
“Yes, sir,” replied Polton. “I will put the mineral section outfit on a tray and bring it down after tea. But can’t I grind the sections? It seems a pity for you to be wasting your time on a mechanical job like that.”
“Thank you, Polton,” replied Thorndyke. “Of course you could cut the sections as well as, or better than, I can. But it is possible that I may have to produce the sections in evidence, and in that case it will be better if I can say that I cut them myself and that they were never out of my own hands. The Courts don’t know you as I do, you see, Polton.”
Polton acknowledged the compliment with a gratified smile and departed to the laboratory. As soon as he was gone Thorndyke brought forth the little cardboard box and having taken out the button, carried it over to the window, where, with the aid of his pocket lens, he made a long and careful examination of the worm-tube; the result of which was to confirm his original observation. The mineral particles of which the tube was built up were of various shapes and sizes, from mere sand-grains up to quite respectable little pebbles. But, so far as he could see, they were all of a similar material. What that material was, an expert mineralogist would have been able, no doubt, to say offhand; and an expert opinion would probably have to be obtained. But in the meantime his own knowledge was enough to enable him to form a fairly reliable opinion when he had made the necessary investigations.
As he drank his tea he reflected on this extraordinary windfall. Circumstances had conspired in the most singular manner against Varney. How much they had conspired remained to be seen. That depended on how much the worm-tube had to tell. But even if no further light were thrown on the matter by the nature of the mineral, there was evidence enough to prove that Purcell had never landed at Penzance. The Terebella had already given that much testimony. And the cross-examination was yet to come.
Having finished tea, he fell to work on the reports and written opinions which had to be completed and sent off by the last post; and it was characteristic of the man that, though the button and its as yet half-read message lurked in the subconscious part of his mind as the engrossing object of interest, he was yet able to concentrate the whole of his conscious attention on the matters with which he was outwardly occupied. Twice during the evening Polton stole silently into the room, once to deposit on a side table the little tray containing the mineral section appliances and the second time to place on a small table near the fire a larger tray bearing the kind of frugal, informal supper that Thorndyke usually consumed when alone and at work.
“If you wait a few moments, Polton, I shall have these letters ready for the post. Then we shall both be free. I don’t want to see anybody to-night unless it is something urgent.”
“Very well, sir,” replied Polton. “I will switch the bell on to the laboratory and I’ll see that you are not disturbed unnecessarily.”