The bearded stranger was watching him closely while his eyes appeared to be focussed upon the object of interest, and presently, as though the psychological moment had arrived, he, too, leant forward, and, with an arm stretched out, terminating in a long, lean, tenacious-looking hand, he pressed a button on the side of the model. Instantly the whole interior of it was lit electrically, and the light shone through a series of exquisitely finished glass-covered port-holes extending down the vessel's entire sides. He spoke no word, but sat back in his chair and went on smoking, while he closely watched for any sign of impression which the two interested spectators displayed. The moments slipped by. The patient stranger sat on with his long lean legs crossed, and a benevolent smile in his large eyes. After a while Ruxton sat back in his chair. Then Sir Andrew abandoned his inspection, and turned to the man beside him. It seemed to be the cue awaited, for the stranger promptly leant forward again and released a spring by the movement of a switch. Instantly the model split in half, and, opening much in the fashion of a pea-pod, displayed the longitudinal sections of its interior. Simultaneously the two men whose lives had been hitherto given up to ship construction rose to their feet, and pored over the wonderful and delicate mechanism and design the interior revealed. Then it was that Sir Andrew verbally broke the silence. "Will you explain, Mr. Smith?" The inventor removed his cigar. "You know--marine mechanism?" he enquired. Sir Andrew nodded. "Yes, unless there is a new principle here." "It is the perfected submarine principle which was used towards the end of the war. There is no fresh detail in that direction." "We have a complete knowledge of that principle," said Ruxton. "We have been constructing for the Admiralty throughout the war." "Good." There was a distinct "T" at the end of the word as Mr. Smith spoke it. Ruxton shot a quick glance in his direction. The man's whole personality was an unusual one. He was very tall, and very thin. His intellectual head, quite nobly formed, was crowned by a shock of snow-white hair closely hogged, as might be a horse's mane. His features were almost as lean as his body. But the conformation of a magnificent forehead and the gently luminous eyes, beneath eyebrows almost as bushy as a well-grown moustache, made one forget the fact. Then, too, the carefully groomed, closely cut snow-white beard and moustache helped to disguise it still more. It was the face of a man of great mentality and lofty emotions, a face of simplicity and kindliness. It was, in fact, a face which demanded a second scrutiny, and one which inspired trust and liking.