"Correct," said Mr. Roumann with a smile. "But sound, as you
know, only goes a little over a thousand feet a second, at a
temperature of thirty-two degrees above zero. In a warmer
atmosphere it travels slightly faster. We are going much faster
than sound ever travels. A cannon ball will travel about three
thousand feet per second, so we are even going to beat cannon
balls. At least, we hope we are, when we get beyond the earth's
atmosphere."

"That's going to be terrific speed," remarked Jack dubiously, as
if there was some risk in it.

"You need not worry," said Mr. Roumann. "You know we are building
the Annihilator with a double shell, with a space between the two
walls."

"Yes?" said Jack questioningly.

"Well, in that space I intend to put a new kind of gas, that will
absorb all the heat that may be generated by our flight through
space," went on Mr. Roumann. "Now that you know you have
nothing to fear, let us go on with the work."





CHAPTER VIII