Yes: like an immense gray sponge the mist had once more advanced, wiping out the vessels slowly sailing into harbour, the far outlying points of land, and now erased an islet called the Nub, mingling all in one confusing cloud.
"All right," said the light-keeper; "we will start the signal."
There was the driving of a stout piston; there was the stirring of a big wheel; there was the movement of other machinery; and there was finally--"What a noise overhead!" thought the listening Dave. It seemed as if five thousand bees all buzzing at once, twenty-five thousand crickets all shrilly piping at once, and fifty thousand wood-sawyers all sawing at once, had combined their noises and were forcing all through the flaming fog-trumpet above. For ten seconds Dave held his fingers in his ears. Then there was a blessed stillness, save as the play of the machinery interrupted it.
"What do you think of that?" asked Mr. Tolman, grinning broadly. "Some lung power left in it yet."
"Lung power! They can hear that down to the Cape of Good Hope. One is enough for both sides of the ocean."
"Want another? Time is ’most up. Here she goes!"
"Toot--buzz--boom--whiz--fizz-z-z--bim-m-m-m!"
Among the breakers tumbling on the sandy shores, along the face of weather-beaten island-edges, down amid the waves and up in the clouds echoed the sharp, strong, fog-piercing, ear-cutting blast. And wherever it went it said, "Of fog I warn-n-n-n-n!" for ten seconds.
In one of the intervals of rest Dave remarked, "Now that must be kept up as long as the fog lasts?"
"Well, that’s how you take it. I was told of a lighthouse where the signal was going twenty-one days."
"Well, there is this side of it: off on the water there is somebody bewildered by the mist, perplexed day after day, it may be, and they catch the sound of the signal. Oh, ain’t that good news? That’s what makes me contented at it. I have sometimes wished I was a musician, and could please others by my playing; but I tell you I have stood by this old engine dark, rainy, foggy nights, and oh, I have been so happy starting up and sending out this old whistle. There it is!"
"Somebody heard that, you may believe, and somebody, too, more pleased than if I had been a whole band of music, and had sent out just the sweetest tune."