- The Planets, Showing their Relative Distances and Dimensions
(Drawn approximately to scale) The isolation of the Solar System is very great. On the above scale the nearest star (at a distance of 25 trillions of miles) would be over one half mile away. The hours, days, and years are the measures of time as we use them; that is: Jupiter's "Day" (one rotation of the planet) is made in ten of our hours; Mercury's "Year" (one revolution of the planet around the Sun) is eighty-eight of our days. Mercury's "Day" and "Year" are the same. This planet turns always the same side to the Sun. - The comparative sizes of the sun and the planets
(Drawn approximately to scale) On this scale the Sun would be 17½ inches in diameter; it is far greater than all the planets put together. Jupiter, in turn, is greater than all the other planets put together. - The Cause of Tides
The tides of the sea are due to the pull of the moon, and, in lesser degree, of the sun. The whole earth is pulled by the moon, but the loose and mobile water is more free to obey this pull than is the solid earth, although small tides are also caused in the earth's solid crust. The effect which the tides have on slowing down the rotation of the earth is explained in the text. - Diagram Showing the Main Layers of the Sun
Diagram Showing the Main Layers of the Sun - A Map of the Chief Plains and Craters of the Moon
The plains were originally supposed to be seas: hence the name "Mare." - A Diagram of a Stream of Meteors Showing the Earth Passing Through Them
A Diagram of a Stream of Meteors Showing the Earth Passing Through Them