A person without mirth is like a wagon without springs

A person without a sense of humor is like a wagon without springs. It's jolted by every pebble on the road.

Channing just projected this warmth and mirth. He was such a happy person. Channing was the kind of person that should've lived to be 100 years old.

I love such mirth as does not make friends ashamed to look upon one another next morning.

The wagon rests in winter, the sleigh in summer, the horse never.

What can promote innocent mirth, and I may say virtue, more than a good riddle?