Aaron Carruthers pointed to his clothes, now ragged and torn. "Look, Karl! Everything I have on is worn out completely. Observe my hair and beard, and the soles of my shoes. Human reason to the contrary, Nanette and I have lived like two animals for four months, and all in the space of fifteen seconds earth time. How can you account for it? We figured it out on paper. And we've proved it with our bodies. What it will mean to future civilization I can't foretell. It's beyond imagination." And the laboratory became silent as a tomb as the three people tried with all the strength of their minds to grasp the miracle of the strange and unfathomable atomic rays. * * * * * PRODUCING HEAT BY ARCTIC COLD Producing heat by means of Arctic cold is a fantastic but none the less quite practicable idea evolved by Dr. H. Barjou of the French Academy of Science. Dr. Barjou says the water under the ice in the Arctic region is about 70 degrees Fahrenheit. While the air is many degrees less, there may even be a difference of 50 degrees. The unfrozen water could be pumped into a tank and permitted to freeze, thus generating heat, as freezing a cubic meter of ice liberates about as much heat as burning twenty-two pounds of coal. The heat produced would vaporize a volatile hydrocarbon which would drive a turbine. For condensing the hydrocarbon again, Dr. Barjou says great blocks of brine could be used. Not only would the Arctic regions become comfortably habitable by means of this utilization of energy, contends Dr. Barjou, but heat also could be furnished for the rest of the world. Now if some one only can discover how to make the Sahara Desert send forth cooling waves, the world will be perfect, temperaturally. Jetta of the Lowlands PART TWO OF A THREE-PART NOVEL _By Ray Cummings_ [Illustration: We were invisible!] [Sidenote: Into remote Lowlands, in an invisible flyer, go Grant and Jetta--prisoners of a scientific depth bandit.] WHAT HAS GONE BEFORE In the year 2020 the oceans have long since drained from the surface of the earth, leaving bared to sun and wind the one-time sea floor. Much of it is flat, caked ooze, cracked and hardened, with, here and there, small scum-covered lakes, bordered by slimy rocks. It is hot, down in the depth of the great Lowland areas, and it is chiefly adventurers and outcasts of human kind who can endure life in what few towns there are. Into Nareda, the capital village of the tiny Lowland Republic of Nareda, goes Philip Grant, an operative of the United States Customs Department, on a dangerous assignment--to ferret out the men who are smuggling mercury into the United States from that place. Grant falls in love with Jetta, the daughter of Jacob Spawn, a big mercury mine owner of Nareda, only to learn that Spawn has promised her in marriage to Greko Perona, the country's Minister of Internal Affairs.