Let us now look forward along the path we are to take. We are standing on the outermost part of our Solar System, and there is no other planet towards which we can wing our flight; but all around are multitudes of stars, some shining with a brightness almost equal to what our Sun appears to give forth at that great distance, others hardly visible, but the smallest telescope increases their number enormously, and presents to our mind the appalling phantom of _immensity_ in all its terror, standing there to withstand our next great step. How are we to continue on our journey when our very senses seem paralysed by this obstruction, and even imagination is powerless from utter loneliness? One guide only is there to help us, the messenger which flits from star to star, universe to universe; Light it is which will help us to appreciate even these bottomless depths. Now, Light travels 186,000 miles per second, or 12 million miles every minute of time. It therefore takes only about four hours to traverse the huge distance between our Sun and Neptune, where we are now supposed to be standing; but to leap across the space separating us from the nearest star, it would require many years for Light, travelling at 186,000 miles every second of that time, to span the distance. There are, in fact, only fifteen stars in the whole heaven that could be reached, on the wings of Light, in sixteen years! Let us use this to continue our voyage. On a clear night the human eye can perceive thousands of stars, in all directions, scattered without any apparent order or design; but in one locality, forming a huge ring round the heavens, there is a misty zone called the Milky Way. Let us turn a telescope with a low aperture on this, and what a sight presents itself! Instead of mist, myriads of stars are now seen surrounded by nebulous haze. We put a higher aperture on, and thus pierce further and further into space; the haze is resolved into myriads more stars, and more haze comes up from the deep beyond, showing that the visual ray was not yet strong enough to fathom the mighty distance; but let the full aperture be applied and mark the result. Mist and haze have disappeared; the telescope has pierced right through the stupendous distance, and only the vast abyss of space, boundless and unfathomable, is seen beyond.