Professor Henderson, however, displayed naught but the keenest interest in the scientific side of the happening. He clambered to his feet the moment he could stand, and observed:
"A most pronounced seismic disturbance—I should say earthquake."
"I should say it was pronounced!" grunted Phineas Roebach. Being a fat man, he had fallen heavily. He was now rubbing himself tenderly where he had been bruised upon the hard ground. "This shock beats the one we had the other day."
"Not a shock, my dear sir," said Professor Henderson, quickly. "An earthquake is not, strictly speaking, a shock at all. Within the past twenty years science has learned to measure and to study earthquakes. If we have learned nothing else, we have learned that an earthquake is not a shock."
"It tumbled us about a whole lot, then, Professor," said Jack Darrow.
"What would you call it, if not a shock?"
The phenomena being over for the time—as all could see—they returned to the cabin to complete their meal. Roebach had said something soothing to his Indians, but they, like Washington White, preferred remaining in the open. Wash sat down beside the cage of his pet rooster, and declared to the boys when they urged him to come in again:
"No, sah! I ain't hongry, nohow. An' w'edder de professor am right dat dese yer earthquakes ain't shockin', I kin tell yo' right now dat it shocked me! Nor I ain't gwine ter gib it no secon' chance ter tumble dat ruff down on ma haid—no, sah!"
Once more at the breakfast table, with the affrighted Indian squaw waiting upon them, the professor took up the topic of earthquakes again, in answer to Jack's observation.
"From the time of the ancients to the middle of the last century the phenomena of earthquakes were observed and described upon countless occasions," he said. "Yet even Humboldt's 'Cosmos', published as late as 1844, which summarized the then existing knowledge on the subject, did not suggest that earthquakes should be studied like other mechanical motions.
"The effects of the great Neapolitan earthquake of 1857 were so studied by Mr. Robert Mallet," continued the professor. "He disabused his mind of all superstition, threw away all the past mysteries, and attacked the problem from its mechanical side only. He believed that an earthquake was a series of shocks, or blows; but what he learned led other and later students to the discovery that an earthquake is not made up of blows at all."