"That's Edison's present problem, Dora. He is such an untiring worker that I don't believe it will take many months; and when the process is perfected and the implements for generating the electricity can be secured, I mean to make my hotel the prettiest place at night on the Maine coast. But meantime, Dora, suppose you learn to wipe lamps so dry and polish chimneys so bright and trim wicks so even that every summer visitor at the 'Atlantic' will be glad to get away for a while from the flaring, ill-smelling, poisonous gas light."
"I will, Uncle John, I will! I'll be the best lamp-trimmer on the whole Maine coast!"
"That's the spirit that will take you to college, Dora," answered her uncle. "Don't lose a bit of it."
For all the long hot weeks of the next summer Dora worked faithfully every day on the hotel lamps. She had to be at her work at eight o'clock every morning, and she seldom finished before two in the afternoon. But every week her uncle paid her three dollars and a half, and by the end of the season she had forty-two dollars carefully put away. When the hotel closed, her uncle made her a present of eight dollars, so that when she started for school in the fall she rejoiced in the thought of fifty dollars put away in the savings bank as a college fund.
She was happy, too, in the prospect of making as much money the next summer. For the Wizard, Uncle John told her, had not the secret yet. He had succeeded in making a platinum wire, encased in a glass globe, give a light equal to that of twenty-five candles without melting. But he needed to exhaust all the air from the glass globe, and still one one-hundred-thousandth of the original volume remained.
"But that's not sufficient," commented Uncle John. "I know enough about the matter to be sure that so much air as that would prevent the platinum from giving out the light it ought to give. Still, within a short time, Dora, I expect even the Portland papers will describe Mr. Edison's success with the electric light."
Uncle John's prediction was fulfilled. By the first of October the vacuum was so nearly perfect that only one-millionth part of the original air was left in the glass bulb. By the last of that same month, moreover, the whole secret was practically in Edison's grasp. He had stopped experimenting with platinum for a burner and had gone back to carbon, on which he had pinned his faith at first.