The present condition of the planet Mars is by no means unpleasant. It is a smaller planet than the Earth and more advanced in age. I do not mean that it is actually older in years, for the whole chain of worlds came into existence , not simultaneously indeed , but within a certain definite area of time. But being smaller it lives its life as a planet more quickly. It cooled more rapidly from the nebulous condition, and it has passed through its other stages with corresponding celerity...