"Not much. The trolley car is a narrow and prescribed manner of using electricity for motive power. The motor runs but one car—or one and a trailer, at most," said Tom. "As I have pointed out, the problem is to build a machine that will transmit power enough to draw the enormous weight of a loaded freight train, and that over steep grades.
"A motor for each car is a costly matter. That is why trolley car companies, no matter how many passengers their cars carry, are so often on the verge of financial disaster. The margin of profit is too narrow.
"But if you can get a locomotive built that will drag a hundred cars! Ah! how does that sound?" demanded Tom. "See the difference?"
"Bless my volts and amperes!" exclaimed Mr. Damon. "I should say I do! Why, Tom, you make the problem as plain as plain can be."
"In theory," supplemented Ned Newton, although he meant to suggest no doubt of his chum's ability to solve almost any problem.
"You've hit it," said Tom promptly. "I only have a theory so far regarding such a locomotive. But to the inventor the theory always must come first. You understand that, Ned?"
"I not only appreciate that fact," said his chum warmly; "but I believe that you are the fellow to show something definite along the line of an improved electric locomotive. But, whether you can reach the high mark set by the president of that railroad—"
"Two miles a minute!" breathed Mr. Damon in agreement. "Bless my wind-gauge! It doesn't seem possible!"
Tom Swift shrugged his shoulders. "It is the impossible that inventors have to overcome. If we experimenters believed in the impossible little would be done in this world, to advance mechanical science at least. Every invention was impossible until the chap who put it through built his first working model."
"That's understood, old boy," said Ned, already busily scratching off the form of the contract he proposed to show the company's legal advisers early in the morning.