When its fuel and water gave out, it descended gently to the river's surface.

In November Langley launched another model which flew for three-quarters of a mile at a speed of thirty miles an hour.

These tests demonstrated the practicability of artificial flight.
The Spanish-American War found the military observation balloon doing the limited work which it had done ever since the days of Franklin.
President McKinley was keenly interested in Langley's design to build a power-driven flying machine which would have innumerable advantages over the balloon.

The Government provided the funds and Langley took up the problem of a flying machine large enough to carry a man.

His initial difficulty was the engine.