In the depths of space, at a distance from the sun more than 30 times our own, under a glow of light and heat 900 times feebler than that which we enjoy, there roams the world of Neptune, among conditions of life quite different from those which obtain on Earth. Those short-sighted naturalists who affirmed even quite recently, with professorial emphasis, that the abysses of the ocean are condemned to an eternal sterility, because the conditions of light and pressure are absolutely different from the conditions near the surface, have received from Nature herself the rudest contradiction which can be inflicted upon the pedantic science of pretenders to infallibility. This contradiction, however direct and absolute, has not discouraged them all, for there are still some who declare that life can only exist on worlds having conditions identical with ours. Always the reasonings of the fish who affirms--quite sincerely--that it is impossible to live outside water! Let us leave these teachers to their illusions and continue our ascent. Astronomy must be the great teacher of philosophy. The distant world of Neptune, on which every year equals nearly 165 of our years, and where ten years represent the whole historical interval which separates us from the Romans (we must remember than 1,650 years ago the Romans reigned at Paris and in Gaul, and neither France nor any of the present-day nations were thought of), this neighbouring world, I say, is well fitted to teach us to enlarge our narrow and personal conceptions, especially as regards the measurement of time. The calendar of that planet is just as exact, just as precise, as ours, and a Neptunian year is not longer to those slow and reflective beings who inhabit the place than is a terrestrial year to those hurrying and agitated persons who swarm in our turbulent cities. Yet a Neptunian adolescent of 20 has really lived nearly 3,300 terrestrial years, without knowing that such a time is called “very long” by the inhabitants of our planet, whom such a life would carry back to the epoch of Homer and ancient Greece.