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.

[In plotting earthquake measurements] the range between the largest and smallest magnitudes seemed unmanageably large. Dr. Beno Gutenberg then made the natural suggestion to plot the amplitudes logarithmically.

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

According to Democritus, truth lies at the bottom of a well, the water of which serves as a mirror in which objects may be reflected. I have heard, however, that some philosophers, in seeking for truth, to pay homage to her, have seen their own image and adored it instead.

Don't wait for extraordinary circumstance to do good; try to use ordinary situations.

It is a common remark that men talk most who think least; just as frogs cease their quacking when a light is brought to the water-side.

Spring makes everything young again except man.