Like icebergs, they cross one another's path, and probably sometimes unite, so as to form a more conspicuous object—thus accounting for the fact, that asteroids have been discovered in localities which were scrutinised with the utmost care a little before, and were found not to exist. It is easy to understand how two bodies, invisible from their smallness, should become a notable object when united. Let us step on one of these miniature worlds, no larger than an English county. With our present muscular strength, we could easily clear the broadest rivers and the loftiest spires—our bodies being literally lighter than a feather. We could readily keep up with the rotation of the asteroid, and prevent the sun from setting. We could have all climates at command. We could withdraw to the polar regions during the heat of the day, and return to the torrid zone to spend the evening. Cyclopean structures might be raised, compared to which, the pyramids of Egypt would be but mole-hills. The very globe itself might be tunnelled and split up, so that contending parties might have little worlds of their own to live in. The imagination can thus easily revel in the wildest fancies, if we exchange the normal conditions of life for extreme physical suppositions. This zone of asteroids serves as the boundary between the two distinct groups of planets. The planets which we have already visited have all distinctive characters, and a family likeness. They are characterised by their greater size and their
