The laboratory echoed and reëchoed deafeningly to the report. And with the explosion sounded the multiple tinkle of falling glass.
Clive’s bullet had had less than seven yards to travel. Yet it had missed his brother by at least two feet. It had flown high above the crouching Osmun’s head and had crashed through one of the vessels on the shelf.
The receptacle shivered by the heavy-caliber ball was a huge Dewar Bulb, silvery of surface. In other words a double container with a vacuum between the outer and inner glass surfaces. Through both layers of thick glass the bullet smashed its way.
The contents of the inner bulb were thus permitted to burst forth and to cascade down upon the luckless man who was crouching for a leap directly below the shelf.
These contents were liquid air.
Among the favorite recreations of the twins in their laboratory had been their constant experiments with liquid air. They had amused themselves by watching it boil violently at a temperature of 150 degrees below zero—of seeing it turn milk into a glowingly phosphorescent mass, of making it change an egg into an oval of brilliant blue light, an elastic rubber band into a brittle stick, and the like.
Because of their constant experiments they always kept an unusually large quantity of the magic chemical in stock, the Dewar Bulb having been made especially for their use at quadruple the customary size.
In its normal state liquid air has a mean temperature of 300 degrees below zero. And now at this temperature it bathed the man on whom it avalanched.
In less than ten seconds Osmun Creede was not only dead but was frozen stiff.
In through the laboratory’s open window gushed the torrid heat of the day, combating and partly quelling the miraculous chill.