us an illustration of the existence of oceans on other planets, so Jupiter provides us with a splendid example of a planet encompassed with clouds.
It is interesting to compare the circumstances attending our residence on this earth with the corresponding conditions that would be found if we could change our abode from this globe to another planet. I propose to discuss a few of the points which arise when we consider such questions. In the first place we must remember that our bodies have been specially organized and adapted to suit our surroundings on this particular world. I do not think it is at all probable that a man could exist, even for five minutes, on any other planet or any other body in the universe. We know that within even the limits of our own earth, each one of us has to be provided with a constitution appropriate to a particular climate. An Eskimo is suitably placed in the arctic regions, a negro on the equator; and were they to change places, it is hard to say whether the heat would not have killed the Eskimo even before the cold killed the negro. But such an attempt at acclimatization would be easy when compared with that which would be required before an inhabitant adapted to one globe could accommodate himself to a residence on another. Indeed, there seem to be innumerable difficulties in supposing that there can be any residence for man, or for any beings nearly resembling man, elsewhere than on his own earth.
Let us specially review a few of the other globes, beginning with the sun. I think we need not give many reasons to show that a man could not live there long. Every boy knows how a burning glass can kindle a piece of paper by concentrating the sun's rays. Some great
