The whole craft shuddered painfully, and its speed began to drop.

Then, as it passed a crossing, its speed began to slacken.

By the early 1930s, the increasing speeds began to make the track more dangerous.

In a few years, when his speed began to fail, then the challenges would start.

He stared at it stupidly for a moment as the speed of his descent began to increase.

His speed was beginning to fall off, and he found himself sweating desperately.

Shortly the train began to move again, very slowly/ the speed of a living creature.

Only as their speed began to edge downward on its own did she touch the brake.

It was happening gradually, but the speed of the process began to increase.

Slowly but perceptibly, the speed of the passing vehicles began to increase.