A man without mirth is like a waggon without springs, in which one is caused disagreeably to jolt by every pebble over which it runs. A man with mirth is like a chariot with springs, in which one can ride over the roughest road, and scarcely feel anything but a pleasant rocking motion.

Henry Ward Beecher (1813-1887) American clergyman and orator

Royal Truths (1862)
    (Source)

Frequently rendered, but unsourced in this form:

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

In Proverbs from Plymouth Pulpit, "The Human Mind" [ed. Drysdale (1887)], Beecher is recorded similarly saying:

A practical, matter-of-fact man is like a wagon without springs: every single pebble on the road jolts him; but a man with imagination has springs that break the jar and jolt.