'We must ask someone with more technical knowledge.' Vogel's bland glance touched on the Saint for a moment with a puzzling dryness, and returned to his protegee. 'Would you like to check over the gear before lunch?'
The Professor knocked out his pipe, and they moved aft. Arnheim stayed in his chair in the shade, with his mouth half open and his hat tilted over his eyes.
Simon fell in beside Loretta and followed the procession. It was the first time that day that he had had a chance to speak to her alone—Vogel had kept her close beside him from the moment they left the harbour, and Arnheim had gone puffing after her with some conversational excuse or other if she had ever moved more than a couple of yards away. The Saint dropped his cigarette, and glanced back as he picked it up. Arnheim had not moved, and his round stomach was distending and relaxing with peaceful regularity . . . Simon rejoined the girl, and slackened his stride.
'Perhaps you heard how I'd been thinking,' he said.
His hand brushed hers as they walked, and he took her fingers and held her back.
'Is this safe?' she asked, hardly moving her lips.
'As safe as anything on this suicides' picnic. It'd be more suspicious if I didn't try to speak to you at all.' He pointed back towards the turreted fortress of the Casquet lighthouse rising from its plinth of rocks to the south, as if he were making some remark about it, and said quietly: 'There's one person who may be sitting on the same volcano as we are; but he doesn't know it.'
'Professor Yule?'
'Yes. Have you thought about him?'
'Quite a lot.'
'It's more than I've done. Until just now. Where does he come in—or go out?'
'I'd like to know.'
'I wish I could tell you. We know Birdie isn't interested in scientific toys. When this new bathystol is passed okay, he'll 've had all he wants out of Yule. Then he'll get rid of him. But how? And how soon?'
He turned away from the lighthouse and they walked on again. Vogel was watching them. The Saint laughed as if at some trivial flippancy, and said in the same sober undertone: 'I'm worried. You can't help liking the old boy. If anything sticky happened to him, I'd feel I had a share in it. If you got a chance you might manage to talk to him. God knows how.'
'I'll try.' She smiled back at him, and went on in her natural voice as they came within earshot of Vogel: 'But it must be hard for the lighthouse-keeper's wife.'
'I expect it is, if she's attractive.'
Simon came to a lazy halt in front of the apparatus which three seamen were manoeuvring out on to the deck—a creation like some sort of weird Martian robot drawn by an imaginative artist. The upper part of it combined torso and head in one great sphere of shining metal, from the sides of which projected arms that looked like strings of huge gleaming beads socketing together and terminating in steel pincers. It balanced on two short bulbous legs of similar construction. The spherical trunk was studded with circular quartz windows like multiple eyes, and tubes of flexible metal coiled round it from various points and connected with a six-foot drum of insulated cable on the deck.
'Is this the new regulation swim suit?' asked the Saint interestedly. 'But it doesn't look as if you could move about in it.'
'It's fairly hard work,' Yule admitted. 'But it looks a great deal heavier than it is. Of course, the air inside helps to take off quite a lot of the weight when it's under water. And then, the whole value of the bathystol is its light construction. Dr Beebe went down more than three thousand feet in his bathysphere in 1934, but he was shut up in a steel ball
'I suppose you do,' said the Saint mildly. 'I don't know what sort of pressures you meet down there——'
'At three thousand feet it's more than half a ton to the square inch. If you lowered a man in an
