"You seem to have some sense, my young friend," he observed. "How would you like to come along and look at the laboratory? I don't suppose Medwin will be here for another twenty minutes." "I should like it very much," said Colin promptly. He rose to his feet, and, dropping the stump of his cigar into the fire, followed his host out of the room and along the hall. On reaching the French windows the Professor turned to the left, and, having descended a couple of steps, pulled up in front of a solid-looking door, which he proceeded to unlock with a Yale key. "This, of course, is not part of the original house," he explained. "I had it built on about twenty years ago, and one way and another it's cost me a pretty penny, I can tell you." He led the way inside, and, with an air of pride that he made no effort to conceal, turned on the electric light. For a private laboratory the place was certainly unique. A large, lofty room, roofed with glass and lined with white tiles, it appeared to have been fitted up with a complete disregard for expense that would have excited envy in the most lavishly endowed American university. For several seconds Colin stood looking round in voiceless appreciation. His eyes wandered in turn over the shining array of taps and switches, the enamelled basins, the big electric furnace, and all the other up-to-date appliances which gleamed invitingly under the hard, unshaded light. At last, with a sigh of satisfaction, he turned to the Professor. "As long as I can work here," he said, "I don't care what I have to eat or drink." Evidently pleased with his companion's enthusiasm, the old man closed the door carefully behind them, and, having replaced the key in his pocket, started off on an explanatory tour of the room. With the absorption of an expert loosed upon his favourite topic, he moved methodically along from one spot to another, stopping in front of each object in turn to explain or demonstrate its various uses. Colin, who was more than content to play the part of a listener, followed him round in absolute silence. Familiar as he was with all the latest developments in research, his acquaintance with many branches was naturally of a rather superficial nature, and, although he was prepared for something of the sort, the apparent depth and accuracy of the Professor's knowledge filled him with amazed respect. To what height this feeling might have attained it is impossible to say, for just as they had arrived at the electric furnace a sudden tap on the door interrupted their proceedings. With an impatient click of his tongue the aged scientist glanced sharply round in the direction of the sound. "Now who the devil's that?" he exclaimed. "I have given orders repeatedly that when I'm in here I am not to be disturbed." He shuffled wrathfully down the room, and, jerking open the door, revealed the lean figure of Mrs. Ramsay. "What's the matter?" he demanded. "Why don't you obey my instructions?"