“I must say I think your father has some good ideas at times,” said Dick. “I suppose they are some scientist friends of his?”

“Yes. Father’s working on some great scheme with these two men,” said George. “One of them’s a genius, apparently, and has hit on an idea that’s too wonderful for words.”

“Which kind of modern idea is it?” said Julian, lazily, holding out his finger-tips for Timmy to lick off smears of ice-cream. “Some space-ship to take us on day-trips to the moon — or some new bomb to set off — or…”

“No. I think it’s something that will give us heat, light and power for almost nothing!” said George. “I heard Father say that it’s the simplest and best idea anyone had ever worked out, and he’s awfully excited about it. He called it a ‘gift to mankind’ and said he was proud to have anything to do with it.”

“Uncle Quentin is very clever, isn’t he?” said Anne. George’s father was the uncle of Julian, Dick and Anne, and they were cousins to George — short for Georgina. Once more they had all come down to Kirrin for part of their holiday, the last three weeks.

George’s father was certainly clever. All the same George sometimes wished that he was a more ordinary parent, one who would play cricket or tennis with children, and not be so horrified at shouting and laughter and silly jokes. He always made a fuss when George’s mother insisted that George should have her cousins to stay.

“Noisy, rowdy, yelling kids!” he said. “I shall lock myself in my study and stay there!”

“All right dear,” said his wife. “You do that. But you know perfectly well that they will be out practically all day long. George must have other children to stay sometimes, and her three cousins are the nicest ones I know. George loves having them here.”

The four cousins were very careful not to upset George’s father. He had a very hot temper and shouted at the top of his voice when he was angry. Still, as Julian said, he really couldn’t help being a genius, and geniuses weren’t ordinary people.

“Especially scientific geniuses who might easily blow up the whole world in a fit of temper,” said Julian, solemnly.

“Well, I wish he wouldn’t keep blowing me up if I let a door bang, or set Timmy barking,” said George.

“That’s only to keep his hand in,” said Dick. “Just a bit of practise at blowing up!”

“Don’t be an ass,” said George. “Does anyone feel like another bathe?”

“No. But I don’t mind going and lying in the very edge of the sea, and letting the waves there just curl over me,” said Dick. “I’m absolutely baked lying here.”

“It sounds lovely,” said Anne. “But the hotter you are the colder the water feels.”

“Come on!” said Dick, getting up. “I shall hang my tongue out and pant like Timmy soon.”

They all went down to the edge of the water and lay down flat in the tiny curling waves there. Anne gave a little shriek.