another vibration of the ether, like light and radiant heat and radio vibrations and the like, having a lower wave-length than any of the others. Suppose we take matter and by applying electrical force to it change its wave-length, step it up to the wave-length of radio vibrations? Then those vibrations can be flashed forth from the sending station to a special receiver that will step them down again from radio vibrations to matter vibrations. Thus matter, living or non-living, could be flashed tremendous distances in a second!

his the Martians told us, and said they would set up a matter-transmitter and receiver on Mars and would aid and instruct us so that we could set up a similar transmitter and receiver here. Then part of us could be flashed out to Mars as radio vibrations by the transmitter, and in moments would have flashed across the gulf to the red planet and would be transformed back from radio vibrations to matter-vibrations by the receiver awaiting us there!

"Naturally we agreed enthusiastically to build such a matter-transmitter and receiver, and then, with their instructions signalled to us constantly, started the work. Weeks it took, but at last, only yesterday, we finished it. The thing's two cubical chambers are one for the transmitting of matter and the other for its reception. At a time agreed on yesterday we tested the thing, placing a guinea pig in the transmitting chamber and turning on the actuating force. Instantly the animal vanished, and in moments came a signal from the Martians saying that they had received it unharmed in their receiving chamber.

"Then we tested it the other way, they sending the same guinea pig to us, and in moments it flashed into being in our receiving chamber. Of course the step-down force in the receiving chamber had to be in operation, since had it not been at that moment the radio-vibrations of the animal would have simply flashed on endlessly in endless space. And the same would happen to any of us were we flashed forth and no receiving chamber turned on to receive us.

"We signalled the Martians that all tests were satisfactory, and told them that on the next night at exactly midnight by our time we would flash out ourselves on our first visit to them. They have promised to have their receiving chamber operating to receive us at that moment, of course, and it is my plan to stay there twenty-four hours, gathering ample proofs of our visit, and then flash back to earth.

"Nelson must stay here, not only to flash us forth to-night, but above all to have the receiving chamber operating to receive us at the destined moment twenty-four hours later. The force required to operate it is too great to use for more than a few minutes at a time, so it is necessary above all that that force be turned on and the receiving chamber ready for us at the moment we flash back. And since Nelson must stay, and Lanier and I wanted another, we wired you, Randall, in the hope that you would want to go with us on this venture. And do you?"

s Milton's question hung, Randall drew a long breath. His eyes were on the two great cubical chambers, and his brain seemed whirling at what he had heard. Then he was on his feet with the others.

"Go? Could you keep me from going? Why, man, it's the greatest adventure in history!"

Milton grasped his hand, as did Lanier, and then the physicist shot a glance at the square clock on the wall. "Well, there's little enough time left us," he said, "for we've hardly an hour before midnight, and at midnight we must be in that transmitting chamber for Nelson to send us flashing out!"

Randall could never recall but dimly afterward how that tense hour passed. It was an hour in which Milton and Nelson went with anxious faces and low-voiced comments from one to another of the pieces of apparatus in the room, inspecting each carefully, from the great dynamos to the transmitting and receiving chambers, while Lanier quickly got out and made ready the rough khaki suits and equipment they were to take.

It lacked but a quarter-hour of midnight when they had finally donned those suits, each making sure that he was in possession of the small personal kit Milton had designated. This included for each a heavy automatic, a small supply of concentrated foods, and a small case of drugs chosen to counteract the rarer atmosphere and lesser gravity which Milton had been warned to expect on the red planet. Each had also a strong wrist-watch, the three synchronized exactly with the big laboratory clock.

hen they had finished checking up on this equipment the clock's longer hand pointed almost to the figure twelve, and the physicist gestured expressively toward the transmitting chamber. Lanier, though, strode for a moment to one of the laboratory's doors and flung it open. As Randall gazed out with him they could see far out over the tossing sea, dimly lit by the great canopy of the summer stars overhead. Right at the zenith among those stars shone brightest a crimson spark.

"Mars," said Lanier, his voice a half-whisper. "And they're waiting out there for us now—out there where we'll be in minutes!"

"And if they shouldn't be waiting—their receiving chamber not ready—"

But Milton's calm voice came across the room to them: "Zero hour," he said, stepping up into the big transmitting chamber.

Lanier and Randall slowly followed, and despite himself a slight shudder shook the latter's body as he stepped into the mechanism that in moments would send him flashing out through the great void as impalpable ether-vibrations. Milton and Lanier were standing silent beside him, their eyes on Nelson, who stood watchfully now at the big switchboard beside the chambers, his own gaze on the clock. They saw him touch a stud, and another, and the hum of the great dynamos at the room's end grew loud as the swarming of angry bees.

The clock's longer hand was crawling over the last space to cover the smaller hand. Nelson turned a knob and the battery of great glass tubes broke into brilliant white light, a crackling coming from them. Randall saw the clock's pointer clicking over the last divisions, and as he saw Nelson grip a great switch there came over him a wild impulse to bolt from the transmitting chamber. But then as his thoughts whirled maelstromlike there came a clang from the clock and Nelson flung down the switch in his grasp. Blinding light seemed to break from all the chamber onto the three; Randall felt himself hurled into nothingness by forces titanic, inconceivable, and then knew no more.

andall came back to consciousness with a humming sound in his ears and with a sharp pain piercing his lungs at every breath. He felt himself lying on a smooth hard surface, and heard the humming stop and be succeeded by a complete silence. He opened his eyes, drawing himself to his feet as Milton and Lanier were doing, and stared about him.

He was standing with his two friends inside a cubical metal chamber almost exactly the same as the one they had occupied in Milton's laboratory a few moments before. But it was not the same, as their first astounded glance out through its open side told them.

For it was not the laboratory that lay around them, but a vast conelike hall that seemed to Randall's