The venerable president entered with his usual book under his arm, for he studied early and late—harder than the “greasiest dig that ever kept the incandescent going,” to quote Holly Cross.
“Ah, young gentlemen,” began Dr. Churchill, blandly, “I presume you are surprised to see me, but your instructor is ill, and I will endeavor to take his place. You are—er—you are in advanced science, are you not? I believe I have the right class,” and the good doctor, somewhat puzzled, consulted a memorandum slip in his hand. “Yes, this is the class,” he went on, with an air of relief. “Now, to-day’s lesson was to be on—er—I’m afraid I have forgotten. Professor Newton told me, but it has slipped my mind.”
It was exactly what Dutch Housenlager had counted on, and he was ready to take advantage of it.
“But of course,” continued the president, with a smile, “you students will know where it is.” He opened the physics book, and leafed it over, as though the lesson would be disclosed to him in some supernatural way. All eyes turned to Dutch, for his impending game had become whispered about.
“I think it’s page three hundred forty-seven, Dr. Churchill,” said Dutch, mentioning a lesson about a week old.
“Ah, yes,” went on the president. “I see. It has to do with heat and cold, sudden changes of temperature and the effects produced by each. Very interesting, very. I trust you are all prepared?”
“If we aren’t, it’s funny,” murmured Dutch, for they had recited on it several times in review.
“Speaking of the changes produced by sudden changes of temperature, can you give me a common example?” asked the president, his eyes roving about the room. Dutch seemed so eager to recite, and have it done with, that his agitation could not but be noticed. “You may answer, Mr. Housenlager,” finished Dr. Churchill.
“Ice and snow,” came the ready reply. Dutch breathed easy again. He thought he was done for the day.
“Very true,” continued Dr. Churchill easily, “but that is a little too common. I referred to the Prince Rupert drops. I dare say you all know what they are. Mr. Housenlager, you will kindly explain to the class how they are made, the effect they produce, and what principle they illustrate.”