Then he explained the apparatus.  It consisted of a miniature head-telephone, connected to a small, metallic case the size of a cigar-box, the cover of which was a transparent diaphragm.  Estra did not open the case, but showed the mechanism through the cover.

“Essentially, this is a ‘word-for-word’ device,” said he, pointing to a swiftly revolving dial within the box.  “On one face of that dial are some ten thousand word-images, made by vibration, after the phonograph method.  Directly opposite, on the other face, are the corresponding words in the other language.  The disk is rotating at such an enormous speed that, for all practical purposes, any word which may chance to be spoken will be translated almost instantaneously.”

He indicated two delicate, many-tentacled “feelers,” as he called them, one on each face of the disk.  One of these “felt” the proper word-image as it whirled beneath, while the other established an electrical contact with the corresponding waves beneath, at the same time exciting a complicated-looking talking machine.

“That,” commented Estra, “is not so easy to explain.  It transforms this literal translation into an idiomatic one.  Perhaps you will understand its workings a little later when you learn how and why I am able to use your own language.”

By this time the four had reached the point where nothing could surprise them.  They were becoming accustomed to the unaccustomed.  Had they been told that the Venusians had abolished speech altogether, they would have felt disappointed, but not incredulous.  However, the doctor thought of something.

“Have you any extra ‘records,’ to be used in case we visit some other nations while we are here?”

For just a second the Venusian was puzzled; then his smile broadened.  “The one record will do,” said he, “wherever you go.”

“A universal language!” Billie’s eyes sparkled with interest.

“Long, long ago,” Estra said.  “It was established soon after our league of nations was formed.”

“Does the league actually prevent war and promote peace?” demanded Van Emmon.  This had been a disputed question when the four left the earth.

“We no longer have a league of nations,” said their guide slowly.  And instantly the four were eying him eagerly.  This was really refreshing, to find that the Venusians were actually lacking in something.

“So it didn’t work?” commented the doctor, disappointed.

But the Venusian’s smile was still there.  “It worked itself out,” said he.  “We have no further use for a league.  We have no more nations.  We are now—­one.”

And he helped them adjust the machines.

The cases were slung over their shoulders and the telephones clamped to their ears.  When all ready, Estra began to talk, and his voice came nearly as sharp and clear through the apparatus as before.  It was modified by a metallic flatness, together with a certain amount of mechanical noise in which a peculiar hissing was the most noticeable.  Otherwise he said: