when, instead of being limited to sixty or seventy years, it extends over hundreds of years, I can readily ascertain my age, from the fact that I was twenty years old at the time these wonderful rays were discovered. I have lived, then, about six hundred of Earth's years, or three hundred Martian years."

"Six hundred years!" I exclaimed, as I looked at the reflection of his handsome face; his eyes flashing, his cheeks aglow with ruddy health, his whole countenance animated with the full vigor of manhood.

"Of course, we do not know how long the effects of regenerating rays will make it possible to live," pursued Almos, "but in theory, it would seem that by their daily use perfect health will be assured, and life itself will continue indefinitely."

"And death become unknown on Mars!" I added, enthusiastically.

"Not quite unknown," rejoined Almos. "For lives are sometimes lost in accidents. Instant death defies all our science, and will not be conquered. But in accidents, no matter how serious, where a spark of life remains, we can prevent that from escaping until the body is in a condition to take care of it.

"This is accomplished by a device known as a virator, which, though simple in construction, is the greatest marvel of the age. It consists of a dome, made of material similar to glass in appearance, but which differs from anything else known, in that it is absolutely atomless. This dome fits over the operating table, upon which the patient lies, with just sufficient room for two persons inside, and is kept at the temperature of the body. On its top is a small globe made of the same material, measuring but a few inches in diameter, which is connected with the large chamber below by a neck or passage about an inch wide. The patient is placed inside, and there operated upon. If life leaves the body, either during the operation or after, the spirit ascends through the narrow passage into the small globe above and is there retained, as it cannot pass through the material of which the walls of this chamber are constructed. The body is then kept continually bathed in the regenerating rays, which not only preserve it as if life were in it, but actually carry on the process of healing. This continues until the body is in a perfectly sound and healthy condition again, and well able to retain life.

"And now occurs the most wonderful of all. When everything is in readiness for the spirit to enter the body again, a strong flow of super-radium is sent through the top globe from an instrument attached. Passing through the small chamber and down the narrow passage, it reaches the body, and immediately changes to a return flow. This current is but momentary; the patient is seen to move, and the body is once more quickened by the life spark. The flow of super-radium has conveyed the spirit of the patient from the small chamber above and released it in the body as it returned, in exactly the same manner as it does with light-waves or sound-waves."

"Marvelous!" I gasped, though my mind could only slowly comprehend this almost miraculous achievement. With such vast scientific resources nothing seemed impossible to Martians.

Almos had stopped abruptly. A change came over him. His face paled and his lips set in a hard, determined expression. Instantly I felt my every faculty strain to the utmost, in response to the new character of this remarkable being.

Speaking slowly and deliberately, his keen eyes holding mine fascinated by a strange fire that seemed kindled within them, he said:

"A few words more and we have reached that point at which death may await the inhabitant of Earth who would proceed farther. A death that no scientific knowledge can avert. I have tried to school your mind, to the end that you may fully understand the nature of a desperate undertaking, never before attempted by any human being, which, if you wish to attempt, you must risk alone.

"Impelled by a motive that I cannot now explain, I have spanned the millions of miles of universe lying between us by a bridge of theories, which, should they prove realities, would enable you to see and live in another world. Should they prove untenable, however, no power on Earth or Mars can save you; in five hours all would be over. You must consider the possible consequences ere it be too late."

"Never!" I cried. "My dear Almos, I am too vitally interested; I have proceeded too far now to hesitate at any step toward such a goal. Explain your theories to me, and I will test them, even if it costs me my life, for Mars holds that which is dearer to me than life on Earth ever can be."

"Well, my brave fellow," said Almos, his voice softening, "you must follow me closely in all I tell you, and remember every word I say, for to-morrow I can be of no assistance to you. Alone you must undertake the journey."

I was glad Almos had not questioned me regarding the import of what I had said in the enthusiasm of the moment, for I could not help feeling now that I had acted unjustly in not confiding in him, at once, the facts regarding the mental image of the beautiful young girl whom I fully believed existed on Mars, and whose destiny, I was certain, was inextricably bound with mine. I now decided to do so on the first opportunity.

"I have explained to you how the spirit may be retained in the upper chamber of a virator after it has left the body," pursued Almos, "and as it is this apparatus we shall employ, I have but to describe the additions I have made to it to meet our requirements, and also my theories in connection with them.

"To the lower chamber or dome of a virator I have connected the receiving apparatus of a radioscope, first removing the image surface. This can be disconnected easily, and the projecting apparatus substituted, from which I have also removed the image surface. Thus we may have a free current of super-radium flowing from the radioscope to Earth and returning into the virator, and by substituting the projecting apparatus, we have a current flowing from the virator to Earth and returning into the receiving apparatus.

"This is exactly the condition that exists in a virator in ordinary use with these exceptions: the current of super-radium is made to flow either in or out of the bottom chamber, as well as the top; instead of being local, the current is between Earth and Mars, and consequently much more powerful. The currents from both the top and bottom chambers are controlled by clockwork which I have devised for that purpose, and in place of an operating table in the virator I have substituted a couch.

"And now I enjoin you to summon all your courage, for in this undertaking nothing but nerves of steel will carry you safely through."

"I shall faithfully carry out your instructions, Almos," I responded, trying to appear perfectly calm, though my being fifteen hundred years behind Martian times never seemed so much a handicap as now.

"Follow me, then, word for word," resumed Almos. "Understand all I say, for in the error of a second, the misconception of a word, the hesitancy of a moment, there is death!

"To-morrow, when that part of the Earth's surface on which Paris is situated appears, I shall attach the receiving apparatus of the radioscope to the lower chamber of the virator, so that the return current from Earth will flow into it. I shall then set the clockwork to turn on the current of super-radium in half an hour. In that time my body must be in a condition to receive your spirit."

I could not suppress a shudder upon hearing this, but I deemed it best not to interrupt Almos.

"Filling a cone with the required amount of chloroform, I shall enter the virator, and, reclining upon the couch, place the cone over my mouth and nose. In a few minutes my spirit will have passed into the upper chamber.

"By experimenting, I have found that regenerating rays are contained in super-radium. In fact, my theory is