I have one red cock that I have on two or three occasions timed by my watch, and counted forty summersaults in the minute.

At first they throw a single summersault, then it is double, till it becomes a continuous roll, which puts an end to flying, for if they fly a few yards over they go, and roll till they reach the ground.
Thus I had one kill herself, and another broke his leg.

Many of them turn over only a few inches from the ground, and will tumble two or three times in flying across their loft.

These are called House-tumblers from tumbling in the house.

The act of tumbling seems to be one over which they have no control, an involuntary movement which they seem to try to prevent.