The common-sense old planter glanced with apprehension at the youth's face, flushed with ardour.
"Have you been much in the sun, Luis?" he asked.
"Oh, he is always talking in that flighty way," Pedro reassured him. "He takes pleasure in it."
"No, my boy," said the planter; "man will never navigate a ship in the sky."
"But on St John's Eve, when we all make bonfires, we also send up little tissue-paper spheres with hot air in them," insisted Luis. "If we could construct a very great one, big enough to lift a man, a light car, and a motor, might not the whole system be propelled through the air, as a steam-boat is propelled through the water?"
"Boys, never talk foolishness!" exclaimed the old friend of the family hurriedly as the captain of the boat approached. It was too late. The captain had heard the boy's observation; instead of calling it folly he excused him.
"The great balloon which you imagine has existed since 1783," he said; "but, though capable of carrying a man or several men, it cannot be controlled—it is at the mercy of the slightest breeze. As long ago as 1852 a French engineer named Giffard made a brilliant failure with what he called a 'dirigible balloon,' furnished with the motor and propeller Luis has dreamed of. All he did was to demonstrate the impossibility of directing a balloon through the air."
"The only way would be to build a flying machine on the model of the bird," spoke up Pedro with authority.
"Pedro is a very sensible boy," observed the old planter. "It is a pity Luis is not more like him and less visionary. Tell me, Pedro, how did you come to decide in favour of the bird as against the balloon?"
"Easily," replied Pedro glibly. "It is the most ordinary-common sense. Does man fly? No. Does the bird fly? Yes. Then if man would fly let him imitate the bird. Nature has made the bird, and Nature never goes wrong. Had the bird been furnished with a great air bag I might have suggested a balloon."