"Now by way of comparison, Astronomers have denominated the Sun as a globe two feet in diameter, or six feet in circumference. Starting from this globe let us wing our way across the space filled by the solar system. A short flight of thirty-seven millions of miles brings us to a world which, compared to the two-feet globe, is no larger than a grain of mustard seed, while it is so bathed in the Sun's dazzling rays that it is not easily distinguished when viewed from the Earth. This fussy little planet whirls round the Sun at the tremendous pace of 100,000 miles an hour, by which he proves his title to be called _Mercury_, the 'swift-footed,' of mythology. At a distance of sixty-eight millions of miles from the Sun we behold _Venus_, the brightest and most dazzling of the heavenly hosts. In comparative size she may be represented as a _pea_. She is our nearest neighbor among the planets, and the conditions under which she exists recall many of those under which we ourselves live. About ninety-five millions of miles from the Sun we come upon another 'pea' a trifle larger than the one representing _Venus_, and in it we hail our own familiar Mother Earth. Here we shall not now linger, but passing onward some fifty millions of miles we are attracted by the well-known ruddy glow of _Mars_--whose comparative size is that of a _pin's head_. His mean orbital speed is 54,000 miles an hour--nearly our own pace--but as he takes twice as much time to run round the Sun as we do, his year is consequently twice as long. "Casting a glance behind, we are reminded of the growing distance that now separates us from the sun by the perceptible waning of his light.