Charles M. Manly was an American engineer who helped Smithsonian Institution

Smithsonian Institution

The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...

 Secretary Samuel Langley build The Great Aerodrome, which was intended to be a manned, powered, winged flying machine.

Manly made major contributions to the development of the aircraft's revolutionary 52 hp gasoline-fueled radial engine, called the Manly-Balzer engine.

Manly attempted to pilot the Aerodome in its only two tests, October and December 1903. The machine failed to fly both times, plunging into the Potomac River

Potomac River

The Potomac River flows into the Chesapeake Bay, located along the mid-Atlantic coast of the United States. The river is approximately long, with a drainage area of about 14,700 square miles...

after its launch from a houseboat. Manly was rescued unhurt, although he was briefly trapped underwater after the second test.