Several points stand out clearly established by the observations of Mars during the opposition of 1894, especially the correctness of Schiaparelli’s discoveries and maps. Most of the canals originally seen by him were again seen, and thus their existence was confirmed, whilst new ones were also noticed. Many of these canals were double. The great extent of the S. Polar cap and its rapid disappearance as Mars’s summer approached was also a special feature of the observations of 1894. It dwindled until it became almost invisible, or at best showed as a tiny speck. It is thought by some observers that as the Polar cap melts, the water collects round the Pole, and thence flows over the planet’s surface, giving rise to the phenomenon of canals, and that this is the way the planet’s surface is irrigated. It may here be remarked that the word “canal,” which has been given to these dark streaks crossing and cutting up the large areas of land in Mars, is an unfortunate one, suggesting as it does artificial agency. But these Martial canals are probably, especially the largest, a great many miles in width and hundreds of miles in length, though some are smaller; and they are probably nature’s method of distributing over the continents and lands of Mars the water which collects round the Pole during the rapid melting of the Polar snows. The idea of the presence of cloud or mist on Mars also received strong confirmation in 1894. Large portions of the planet’s disc were found to be hidden from view. “Herschel I. Continent” and the “Maraldi Sea” (both well-known markings on Mars, readily visible with small telescopes) were at times quite obscured by cloud. Indeed, the Maraldi Sea was occasionally quite blotted out: other well-known markings were also either blotted out or only faintly seen. These facts seem almost to prove conclusively the existence of cloud and vapour in Mars, especially as some of these markings subsequently again assumed their ordinary form and colour. Bright projections too were seen at times on the terminator of Mars, giving rise to the belief that there are high mountains on the planet, though some observers regarded these projections as high clouds powerfully reflecting the Sun’s light. Mars rotates on its axis in 24h. 37m. 22s., a period so nearly coincident with the period of the Earth’s rotation as greatly to facilitate the mapping of Mars’s features by work continued from day to day by observers who have the necessary instrumental means and artistic skill in handling the pencil. Mars has an atmosphere which may be said to be no more than moderately dense; that is to say much less dense than the Earth’s atmosphere. Of course the existence of snow, which has been taken for granted on a previous page, carries with it the existence of water and aqueous vapour—a fact capable of independent spectroscopic proof.