Spark handed the bag to Clancy, and the latter poured some of the nitroglycerin into the cup.
Then, crouching under one of the counters, they waited while the explosive oozed downward about the vault door on the inside.
“Give me the fuse,” said Clancy, emerging from under the counter when a sufficient period had elapsed.
Again he mounted the stool, fitted a cap to the end of the fuse, placed the cap in the cup and applied a match.
Both retreated for a short distance.
Presently there came a muffled explosion, resulting in the bursting open of the vault door.
The alarm was silent, proving that Spark had done his work well.
For several moments, however, neither of the robbers made a move—simply crouched where they were and listened intently.
There was no sound outside, so it was evident that the explosion had aroused no one.