"Not for many days yet," laughed the doctor. "The worst of the job is over, I'll admit, but there's still plenty to do. It will be over a week before the last car-loads of matter reach the surface here, and in the mean time I must set about welding the two tubes together in the center."
"H'm!" commented Mr. Curtis, "that will indeed be a delicate job. I suppose you will have to send a gang of workmen down into the tube to attend to that."
"Not on any account," returned Dr. Giles, quickly. "Up to the present moment, as you know, I have not been obliged to send workmen down to any distance below the surface of the earth, and even now this will not be necessary. I purposely prepared the bottoms of the tubes so that I can, when I so desire, weld them together electrically, without any one being obliged to go down into the tube. By merely pressing certain buttons here in my office the proper connections will be made."
"I am glad of that, for the sake of the workmen," said Mr. Curtis; "but in some ways it is a pity that no one will go down into the tube, for it would be quite a novel sensation to be down at the center of the earth, where there is no attrac-
