“When it is over, with pleasure,” Sir Meyville assented.

Granet stepped into his car and drove off.  The inventor stood looking after him.  Then he spoke to the sentry and made his way across the gardens towards the boat-shed.

“I ought to have known it from the first,” he muttered.  “Reciprocal refraction was the one thing to think about.”

Granet, as he drove back to the Dormy House, was conscious of a curious change in the weather.  The wind, which had been blowing more or less during the last few days, had suddenly dropped.  There was a new heaviness in the atmosphere, little banks of transparent mist were drifting in from seawards.  More than once he stopped the car and, standing up, looked steadily away seawards.  The long stretch of marshland, on which the golf links were situated, was empty.  A slight, drizzling rain was falling.  He found, when he reached the Dormy House, that nearly all the men were assembled in one of the large sitting-rooms.  A table of bridge had been made up.  Mr. Collins was seated in an easy-chair close to the window, reading a review.  Granet accepted a cup of tea and stood on the hearth-rug.

“How did the golf go this afternoon?” he inquired.

“I was dead off it,” Anselman replied gloomily.

“Our friend in the easy-chair there knocked spots off us.”

Mr. Collins looked up and grunted and looked out of the window again.

“Either of you fellows going to cut in at bridge?” young Anselman continued.

Granet shook his head and walked to the window.

“I can’t stick cards in the daytime.”

Mr. Collins shut up his review.

“I agree with you, sir,” he said.  “I endeavoured to persuade one of these gentlemen to play another nine holes—­unsuccessfully, I regret to state.”

Granet lit a cigarette.

“Well,” he remarked, “it’s too far to get down to the links again but I’ll play you a game of bowls, if you like.”

The other glanced out upon the lawn and rose to his feet.

“It is an excellent suggestion,” he declared.  “If you will give me five minutes to fetch my mackintosh and galoshes, it would interest me to see whether I have profited by the lessons I took in Scotland.”

They met, a few moments later, in the garden.  Mr. Collins threw the jack with great precision and they played an end during which his superiority was apparent.  They strolled together across the lawn, well away now from the house.  For the first time Granet dropped his careless tone.

“What do you make of this change in the weather?” he asked quickly.

“It’s just what they were waiting for,” the other replied.  “What about this afternoon?”

“I am not scientist, worse luck,” Granet replied impatiently, “but I saw enough to convince me that they’ve got the right idea.  Sir Meyville thought I was the man commanding the escort they’ve given him,—­actually rowed me out to the workshop and showed me the whole thing.  I tell you I saw it just as you described it,—­saw the bottom of the sea, even the colour of the seaweed, the holes in the rocks.”