Chapter XII. The Try-Out Day Arrives - Page 2

else will!"

For Tom to think of a thing was to start action without delay. Immediately he called a gang from the shops and set them to work stringing copper wire along the top of the stockade.

He was sure that the man who had set the time bomb in place had got into the enclosure over the fence. If he tried the same trick again he was very apt to have the surprise of his life!

Each night when the shops closed and the watchmen went on duty, a current of electricity was turned into those copper wires entwined with the barbed wire entanglement at the top of the stockade that would certainly double up any marauder who sought to get over the top.

However, no further attempt was made against Tom's peace of mind and against his invention during the immediate weeks that followed. The young inventor was so closely engaged in his work that he scarcely left the house or the confines of the shops. Even Mary Nestor saw very little of him.

But Mary realized fully that at such a time as this Tom must give all his thought and energy to the task in hand. She was proud of Tom's ability and took a deep interest in his inventions.

"I want to see the test when you try the locomotive, Tom," she told him, when she came to the shops the first time to look at the monster locomotive. "What a wonderful thing it is!"

"Its wonder is yet to be proved," rejoined the young inventor. "I believe I've got the right idea; but nothing is sure as yet."

In addition to his mechanical contrivances inside the locomotive, Tom had to arrange for an increased supply of electric power to drive the huge machine around the track that was being built inside the stockade.

A regular station had to be built for receiving the electricity in a 100,000-volt alternating current and delivering it to the locomotive in a 3,000-volt direct current. Therefore, this station had two functions to perform--reducing the voltage and changing the current from alternating to direct.

The reduction of the voltage was accomplished as follows: The 100,000-volt alternating current was received through an oil switch and was conveyed to a high-tension current distributor made up of three lines of copper tubing, thus forming the source of power for this station.

From the current distributor the current was conducted through other oil switches to the transformers--entering at 100,000 volts and emerging at 2,300 volts. Then the current was conducted from the transformers through switches to the motor-generator sets and became the power employed to operate them.

The motor generator consisted of one alternating current motor driving two direct current generators. The motor Tom established in his station was of the 60-cycle synchronous type, which means that the current changes sixty times each second.

There were two sets, each generating a