Every formula which expresses a law of nature is a hymn of praise to God.

But why look back at all? Why turn your eyes to your shadow, when, by looking upward, you see your rainbow in the same direction?

I am just learning to notice the different colors of the stars, and already begin to have a new enjoyment.

The greatest object in educating is to give a right habit of study.

I was a little doubtful about the propriety of going to the Mammoth Cave without a gentleman escort, but if two ladies travel alone they must have the courage of men.

Do not look at stars as bright spots only. Try to take in the vastness of the universe.

I was born, for instance, incapable of appreciating music.