§ 28. Among the Planets _Venus_ is by far the most beautiful in appearance. She is known also by the name of the _Morning_ and _Evening Star_. Her light is so bright that she is often seen at _Noon_. When viewed through a good telescope she exhibits phases similar to those of the Moon (Lesson III, § 17), which proves her spherical form (Lesson I, § 3). The mountains in Venus have been calculated to be at least Six times as high as those on our Earth. Her Atmosphere is only half as dense as ours. § 29. Mars appears in many respects similar to our Earth. His light is red and changeable; his surface exhibits black changeable spots (see Figure II, Plate X). Some philosophers pretend to have noticed a region of ice on his poles. His atmosphere is twice as dense as ours. [Illustration: _N^o. X._ ] § 30. Jupiter, viewed through a telescope, exhibits a surface covered with stripes. These are supposed to be clouds. A representation of them is given in Fig. III, Plate X. His light is very white and subject to but little variation. His atmosphere is nearly Twentyseven times denser (thicker) than ours. § 31. Very remarkable, as we have already observed, is the Planet Saturn, on account of its luminous ring. Viewed through a telescope it has the appearance, represented in Figure IV. It is highly probable that to the inhabitants of that Planet, this ring has an entirely different appearance from what it has to us. It appears to be a solid opaque mass, and is probably inhabited like the Planet, which it constantly accompanies on its journey round the Sun. Saturn’s atmosphere is nearly Ninety times denser than that of our Earth. No mountains have as yet been discovered on its surface. * * * * * Herschel is too remote, for us to know much about its surface. Its atmosphere is supposed to be Three Hundred and Sixty-one times thicker than ours. Mercury, being the nearest Planet to the Sun, has a very bright light; but is only seen early before Sun-rise, and immediately after Sun-set. It exhibits Phases like the Moon. RECAPITULATION OF LESSON V. QUESTIONS. [§ 27.] What do you know about the Moon’s surface? What, about its mountains, volcanos and caverns? Have any great waters been discovered in it? [§ 28.] What do you know about the Planet Venus? By what other name is she known? What does she exhibit, when viewed through a telescope? What do you know about her mountains? What, about her atmosphere? [§ 29.] What do you know about the Planet Mars? What, about his light, surface and atmosphere? [§ 30.] What surface does Jupiter exhibit when viewed through a telescope? Of what color is the light of Jupiter? What do you know about his atmosphere? [§ 31.] What do you know about the Planet Saturn? What does the ring of Saturn appear to be? What do you know about the atmosphere of this Planet? FOOTNOTES: