That hemisphere of the moon which faces us is better known than the earth itself; its vast desert plains have been surveyed to within a few acres; its mountains and craters have been measured to within a few yards; while on the earth's surface there are 30,000,000 square kilometres (sixty times the extent of France), upon which the foot of man has never trod, which the eye of man has never seen.

Lightning is like an elementary spirit, eccentric or rational, clever or silly, passing from one extreme to the other.

If humankind - from humble farmers in the fields and toiling workers in the cities to teachers, people of independent means, those who have reached the pinnacle of fame or fortune, even the most frivolous of society women - if they knew what profound inner pleasure awaits those who gaze at the heavens, then France, nay, the whole of Europe, would be covered with telescopes instead of bayonets, thereby promoting universal happiness and peace.

The present inhabitation of Mars be a race superior to ours is very probable.

Men have had the vanity to pretend that the whole creation was made for them, while in reality the whole creation does not suspect their existence.

What, then, is this blue sky, which certainly does exist, and which veils from us the stars during the day?

The universe is so immense that it appears immutable, and that the duration of a planet such as that of the earth is only a chapter, less than that, a phrase, less still, only a word of the universe’s history.