But an incident now transpired to put a stop to the entire project. This happening was a most startling and unlooked for one.

Suddenly the Dart received a shock which seemed to fairly hoist it a dozen feet from the bottom of the sea.

Everybody on board were thrown from their feet.

Then followed a distant rumble and a vibrating motion which lasted for full a minute.

In some way the shock had disconnected the lever, and the electric lights were extinguished.

All was darkness aboard the submarine boat.

For a few moments a literal panic reigned.

Frank Reade, Jr., was the first to recover.

He ran into the pilot-house and quickly produced light. By this time the others had recovered.

“For the love of Heaven! what has happened?” gasped Von Bulow.