mped 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.

Grant follows Perona to a midnight Lowland rendezvous with mysterious
strangers and eavesdrops on them, sending their indistinct voice
murmurs to his chief, Hanley, in Washington, who relays them back to
him, amplified. He learns several important things: that Spawn and
Perona and a depth bandit named De Boer are together involved in the
smuggling; that they have planned a fake robbery of a fortune in
radiumized mercury stored at Spawn's mine, to collect the insurance on
it and escape paying the Government export fee: and that they, plan
to kidnap Grant for ransom.

The plotters learn of Grant's absence from Nareda,