I followed Jim out of the laboratory and to a large open space behind the main building where the infra-red generators with which he had pierced the hole through the heaviside layer had been located. The reflectors were still in place, but the bank of generators had been removed. A gang of men were hard at work erecting a huge parabolic reflector in the center of the circle, about the periphery of which the infra-red reflectors were placed. In an open space near the center stood a Hadley space ship, toward which Jim led the way.
I wondered at the activity and meant to ask what it portended, but in the excitement of boarding the flyer forgot it. I followed Jim in; he closed the door and started the air conditioner.
"Here, First Mortgage," he said as he turned from the control board and faced me, "here are the fluoroscopic screens. They are arranged in a bank, so that you can keep an eye on all of them readily. Beneath each telescope is an automatic one-pounder gun with its mount geared to the telescope and the light, so that the gun bears continually on the point in space represented by the center of the fluoroscopic screen which belongs to that light. If we locate anything, turn your beam until the object is in the exact center of the screen where these two cross-hairs are. When you have it lined up, push this button and the gun will fire."
"What about reloading?"
"The guns are self-loading. Each one has twenty shells in its magazine and will fire one shot each time the button is pushed until it is empty. If you empty one magazine, I can turn the ship so that another gun will bear. This gives you a total of one hundred and twenty shots quickly available; there are sixty extra rounds, which we can break out and load into the magazines in a few seconds. Do you understand everything?"
"I guess so. Everything seems clear enough."
"All right; sit down and we'll start."
I took my seat, and Jim pulled the starting lever. I was glued to the seat and the heavy springs in the cushion were compressed almost to their limit by the sudden acceleration. As soon as we were well clear of the ground Jim reduced his power, and in a few moments we were floating motionless in the air, a thousand feet up. He left the control board and came to my side.