"Oh yes," said Mrs. Van Stuyler rather acidly, "and not only in the abstract ideas, but apparently in a certain concrete reality."

"Mrs. Van," laughed Zaidie, with a cunning twist on her heel, "I know you don't mean to be rude, but—well, now did any one ever call you a concrete reality? Of course it's correct just as a scientific definition, perhaps—still, anyhow, I guess it's not much good going on about that. The facts are just this way. I consented to marry that Byfleet marquis just out of sheer spite and blank ignorance. Lord Redgrave never actually asked me to marry him when we were in the Rockies, but he did say when he went back to England that as soon as he had realised my father's ideal he would come over and try and realise one of his own. He was looking at me when he said it, and he looked a good deal more than he said. Then he went away, and poor Pop died. Of course I couldn't write and tell him, and I suppose he was too proud to write before he'd done what he undertook to do, and I, like most girl-fools in the same place would have done, thought that he'd given the whole thing up and just looked upon the trip as a sort of interlude in globe-trotting, and thought no more about Pop's ideas and inventions than he did about his daughter."

"Very natural, of course," said Mrs. Van Stuyler, somewhat mollified by the subdued passion which Zaidie had managed to put into her commonplace words; "and so as you thought he had forgotten you and was finding a wife in his own country, and a possible husband came over from that same country with a coronet——"

"That'll do, Mrs. Van, thank you," interrupted Miss Zaidie, bringing her daintily-shod foot down on the deck this time with an unmistakable stamp. "We'll consider that incident closed if you please. It was a miserable, mean, sordid business altogether; I am utterly, hopelessly ashamed of it and myself too. Just to think that I could ever——"

Mrs. Van Stuyler cut short her indignant flow of words by a sudden uplifting of her eyelids and a swift turn of her head towards the companion way. Zaidie stamped again, this time more softly, and walked away to have another look at the clouds.

"Why, what on earth is the matter?" she exclaimed, shrinking back from the glass wall. "There's nothing—we're not anywhere!"

"Pardon me, Miss Rennick, you are on board the Astronef," said Lord Redgrave, as he reached the top of the companion way, "and the Astronef is at present travelling at about a hundred and fifty miles an hour above the clouds towards Washington. That is why you don't see the clouds and sea as you did after we left the St. Louis. At a speed like this they simply make a sort of grey-green blur. We shall be in Washington this evening, I hope."

"To-night, sir—I beg your pardon, my Lord!" gasped Mrs. Van Stuyler. "A hundred and fifty miles an hour! Surely that's impossible."

"My dear Mrs. Van Stuyler," said Redgrave, with a side-look at Zaidie, "nowadays 'impossible' is hardly an English or even an American word. In fact, since I have had the honour of realising some of Professor Rennick's ideas it has been relegated to the domain of mathematics. Not even he could make two and two more or less than four, but—well, would you like to come into the conning-tower and see for yourselves? I can show you a few experiments that will, at any rate, help to pass the time between here and Washington."

"Lord Redgrave," said Mrs. Van Stuyler, dropping gracefully back into her wicker armchair, "if I may say so, I have seen quite enough impossibilities, and—er, well—other things since we left the deck of the St. Louis to keep me quite satisfied until, with your lordship's permission, I set foot on solid ground again, and I should also like to remind you that we have left everything behind us on the St. Louis, everything except what we stand up in, and—and——"