“In an ordinary marine boiler the flame goes through the flues; in the water-tube pattern the water circulates in tubes and the flame is outside. The type has some drawbacks I mustn’t bother you about, but it steams fast and carries a heavy pressure. Well, a foreign government requires four small, swift, shallow boats for tropical rivers and has ordered two; one from us, and one from the opposition yard.”
Mrs. Blake nodded. “The Mariposa’s yours; if she beats the other boat, you will build the lot?”
“Colvin hopes we’ll do so. The rivers she’ll navigate are muddy, and in a water-tube boiler mud is awkward. We have been forced to modify our standard pattern, but if we get the results we expect, we reckon on beating the other boat. The improvements cannot be patented, and in consequence we don’t talk about our plans.”
“But if the Mariposa wins, your competitors may bribe somebody to study her boiler.”
“It’s possible,” Kit agreed. “All the same, the tubes are covered by a casing, and if the opposition did find out something useful, we’d have begun to build the fleet. Now you know all about it and we have done with shipbuilding. Let’s try the new piano!”
He went to the piano and began to play. The others knew his talent, but they thought the music strange and melancholy. Yet the air was haunting.
“It is not piano music,” Blake remarked.
“I expect it was first written for the guitar; Spanish music’s Moorish music. Don’t you hear the strings and the wind in the sand? Can’t you picture the camel-dung fires in front of the black tents, and smell the curling smoke. But I’ll try a song. It’s about the King of Spain who lost Gibraltar, but did not lose all the fellow lost who lost his heart. Do you hear the guitars tinkle under the lattice window?”
“I do not,” said Blake, smiling. “Still, you see, I’m not a lute player.”
“Oh, well, the next lot’s blatantly pictorial,” said Kit and pushed down the pedal. “Shipyard hammers! You can hear that! Now the Negapatam’s whistle calls in the smoke and fog. She steals down river; her screw throbs steadily and stops. The pilot’s boat vanishes and the engines beat a quicker rhythm. The dark water heaves and splashes at the bows. She steers south for sunshine and the islands of pearls and spice.”