“When we speed her up she begins to smoke like—”
“She does smoke pretty badly,” interjected Tommy.
“Why?” asked Jenkins.
“Damfino!” said Bill, crossly. It had been a source of exasperation to him.
“That is what we are here to find out, sir,” put in Tommy, deferentially.
“I've tried every blamed thing I could think of,” said Bill. “If I only knew why she works below nine hundred I might make it work when I speed her up.”
“H'm!” The professor was thinking over what Bill had told him. Then he said: “Well, you evidently are using a very high current. I suspect there must be some ionization there.” He paused. Then, more positively: “I think you undoubtedly are ionizing the vapor. That would account for what results you say you are getting.”
“What is it that happens?” asked Bill, eagerly.
Professor Jenkins delivered a short lecture on the ionization of gases, a subject so dear to his heart that when he saw how absorbingly they listened he took quite a personal liking to them. He suggested a long series of tests and experiments, which Tommy jotted down in his own private system of Freshman shorthand. At one of them Bill shook his head so despairingly that Professor Jenkins told him, kindly:
“If you care to have us make any of the tests for which you may lack the proper appliances, we shall be glad to undertake them for you here.”