minute! We'll have more diamonds than we ever had before!"
"Yes, if the mountain isn't destroyed," added Mr. Parker, in a low voice. "I predict that it will be split from top to bottom!"
"Comforting," thought Tom, grimly.
"I guess we're all ready," said Folwell, in a low tone to Munson. "We'd better get insulated ourselves. I'm going to throw the switch."
He did so. A moment later the man who had before given warning of the storm came dashing in. He was very much excited.
"It's awful!" he cried. "The lightning is striking all over! Big rocks are being split like logs of wood!"
"Well, it can't do any damage in here," said Munson. "We are well protected. Get on one of the plates," and he motioned to one of the hard-rubber platforms that was not occupied. The roar and rumble of the storm outside had given place to short terrific crashes. In their small cave the adventurers could feel the solid ground shake.
A bluish light began dancing about the electrical wires. There was a smell of sulphur in the air. Crash after crash resounded outside. A
