73. Parley tells about Telescopes. About Microscopes. About the general Wonders of Creation 74. Parley speaks about the Changes that are always taking place on the Earth and in the Heavens. The Royal 75. Parley describes at full length the Monster Telescope of Lord Rosse. The principle of the Reflecting Telescope. Sir James South's description of the Great Telescope. 76. Parley shows how the Distance to the Moon has been shortened. The Upheaving Power in the Earth and Moon set forth. Remarkable Appearances in the Moon. 77. Parley tells of the Discovery of New Planets. The Planet Neptune. Different Claimants for the Credit of the Dis- 78. Thanks to Illustrious Astronomers and Mathematicians. Newton and his Dog Diamond. History of James Fer- guson. His Poverty and Self-education. King George the Third seeks to be instructed by him in Astronomy. Possible Influence of the early Genius and Industry of Ferguson upon all the subsequent Progress of Astrono- mical Discovery in Europe to this day. Love and Pa- tronage of Arts, Sciences, and Letters, by King George 1. HERE is a picture of a balloon. It is an immense bag of silk, as big as a small house. A net is thrown B over it. To the bottom of this net is attached a little car, in figure like a boat. 2. The balloon is filled with gas, which is kind of rarefied air. This gas is very light, and as it rises up, it takes the balloon, car and all, up with it. Two of the persons in the car carry each a flag in his left hand. 3. The balloon has just begun to ascend. It is now no higher than the top of a house. A great many people are standing below, looking at the balloon. They can distinctly see the little car, and the aëronauts in it. They can see the little flags, which they are waving in their hands. They can see the network that is over the balloon, and can easily distinguish the countenances of the adventurous persons who are now taking a ride into the regions of the clouds. 4. Well! the balloon rises higher and higher! it is soon far above the tops of the highest steeples. How small it looks! The little flags in the aëronauts' hands are not to be seen. The aeronauts themselves appear like specks, and the car is scarcely visible. 5. Still it continues to pierce further and further into the regions of air; it is borne along by the wind, and passes rapidly away over the hills and valleys, and woods and meadows, and villages and towns. 6. Look! here is still another picture of the balloon. How very small it appears to be! It seems scarcely bigger than a pin's head. It is, you see, higher than the clouds, and I suppose is now about twenty miles off. We can see nothing but a dark speck; yet we know that it is the same balloon; we know that it is very large; we know that it has a car attached to it; and that several men are riding along with it. 7. Now, what is the reason that this balloon appears so very small? Why cannot we see the car and the men? You will tell me it is because they are so far off. Very well! that is what I wish you to remember. Anything a great way off, appears, smaller than it really is. A balloon, that is as big as a small house, does not look bigger than a pin's head, when it is twenty miles off. 1. Describe a balloon. 2. What carries up a balloon into the air? 6. How large does a balloon appear to be, high in the air, and at the distance of twenty miles? 7. Why does a balloon look so small, at the distance of twenty miles? |