itrogen
atmosphere in my transformer and replace the quartz bulb with a capsule
of zircorundum."

"A capsule of what?" asked Thornton, whose chemistry was mid-Victorian.

"Zircorundum," said Bennie, groping around in a drawer of his work
table. "It's an absolute nonconductor of heat. Look here, just stick
your finger in that." He held out to Thornton what appeared to be a
small test tube of black glass. Thornton, with a slight moral
hesitation, did as he was told, and Bennie, whistling, picked up the
oxyacetylene blowpipe, regarding it somewhat as a dog fancier might gaze
at an exceptionally fine pup. "Hold up your finger," said he to the
astronomer. "That's right--like that!"

Thrusting the blowpipe forward, he allowed the hissing blue-white flame
to wrap itself round the outer wall of the tube--a flame which Thornton
knew could melt its way through a block of steel--but the astronomer
felt no sensation of heat, although he not unnaturally expected the
member to be incinerated.

"Queer, eh?" said Bennie. "Absolute insulation! Beats the thermos
bottle, and requires no vacuum. It isn't quite what I want though,
because the disintegrating rays which the ring discharge gives out break
down the zirconium, which isn't an end-product of radioactivity. The
pressure in the capsule rises, due to the liberation of helium, and it
blows up, and the landlady or the police come up and bother me."

Thornton was scrutinizing Bennie's rough diagram. "This ring discharge,"
he meditated; "I wonder if it isn't something like a sunspot. You know
the spots are electron vortices with strong magnetic fields. I'll bet
you the Savaroff disintegrating rays come from the spots and not from
the whole surface of the sun!"

"My word," said Bennie, with a grin of delight, "you occasionally have
an illuminating idea, even if you are a musty astronomer. I always
thought you were a sort of calculating machine, who slept on a logarithm
table. I owe you two drinks for that suggestion, and to scare a thirst
into you I'll show you an experiment that no living human being has ever
seen before. I can't make very powerful disintegrating rays yet, but I
can break down uranium, which is the easiest of all. Later on I'll be
able to disintegrate anything, if I have luck--that is, anything except
end-products. Then you'll see things fly. But, for the present, just
this." He picked up a thin plate of white metal. "This is the metal
we're going to attack, urani