mania.  It worried him a good deal; he didn’t understand it.  That, then, was what ailed Pulz.  When he opened the chest there was, as I surmise, a trifling quantity of this stuff lying in the inner lid.  It wasn’t the celestium itself, as I imagine, but a sort of by-product with the physiological and radiant effects of the real thing, and it had been set there on guard, a discouragement to the spirit of investigation, as it were.  So, when the top was lifted, our little guardian gets in its work, producing the light phenomenon that so puzzled Slade, and inspiring Pulz with a passion for the rolling wave, which is only interrupted by Handy Solomon’s tackling him.  As he fled he must have pulled down the cover.”

“He did,” said Slade.  “I heard the clang.  But I saw the radiance on the clouds.  And the whole thickness of a solid oak deck was in between the sky and the chest.”

“Oh, a little thing like an oak deck wouldn’t interrupt the kind of rays the doctor used.  He had his own method of screening, you understand.  However, this inconsiderable guardian affair must have used itself up, which true celestium wouldn’t have done.  So when Perdosa sets his genius for lock-picking to the task, the inner box, full of the genuine article, has no warning sign-post, so to speak.  Everything’s peaceful until they raise the compound-filled hollow layer of the inner cover, which serves to interrupt the action.  Then comes the general exit and the superior fireworks.”

“That’s when the rays ran through the ship,” said Slade.  “It seemed to follow the deck-lines.”

“The stuff had a strange affinity for tar,” said Darrow.  “I told you of the circle of fire about Professor Schermerhorn’s waist the day he gave me such a scare.  That was the celestium working on the tarred rope he wore for a belt.  It made a livid circle on his skin.  Did I tell you of his experiments with pitch?  It doesn’t matter.  Where was I?”

“At the place where we all jumped,” said Slade.

“Oh, yes.  And you dove into the small boat, trying to reach the water.”

“Wait a bit,” said Barnett.  “If that was the exhibition of radiance we saw, it died out in a few minutes.  How was that?  Did they close the chest before they ran?”

“Probably not,” replied Darrow.  “Slade spoke of Pulz taking to the maintop and being shaken out by the sudden shock of a wave.  That may have been a volcanic billow.  Whatever it was, it undoubtedly heeled the ship sufficiently to bring down both lids, which were rather delicately balanced.”

“Yes, for Billy Edwards found the chest closed and locked,” said Barnett.