The most remarkable feature about the magnitude scale was that it worked at all and that it could be extended on a worldwide basis. It was originally envisaged as a rather rough-and-ready procedure by which we could grade earthquakes. We would have been happy if we could have assigned just three categories, large, medium, and small; the point is, we wanted to avoid personal judgments. It actually turned out to be quite a finely tuned scale.

Refining is inevitable in science when you have made measurements of a phenomenon for a long period of time.

Most loss of life and property has been due to the collapse of antiquated and unsafe structures, mostly of brick and other masonry. ... There is progress of California toward building new construction according to earthquake-resistant design. We would have less reason to ask for earthquake prediction if this was universal.

Nothing is less predictable than the development of an active scientific field.

There is nothing more beautiful than cheerfulness in an old face, and among country people it is always a sign of a well-regulated life.

Remembrance is the only paradise out of which we cannot be driven away.

If one introduces the concept of energy of an earthquake then that is a theoretically derived quantity.