Fire
A gift of the gods. According to an old Greek myth, Prometheus and his brother, Epimetheus, heroes of a race of giants called the Titans, were given the task of creating man. Epimetheus was also to provide all the animals with means of defense or flight. To some he gave courage, strength, and claws with which to fight, and to others long legs, nimble feet, or wings with which to escape. So lavish was he with these gifts to the lower animals that he had nothing left to give to man. Prometheus, however, was determined that man should not be neglected and so, according to the myth, he gained access to heaven and lighted his torch at the chariot of the sun. Returning to earth, he presented fire to man, and with this gift came mans dominion over all the earth.
The first cook. It took a long time, however, to learn how to use this gift. For centuries men lived like wild animals. Their food consisted of nuts, herbs, fruit, and the flesh of animals. Cooking was unknown, and when a wild animal was captured, the savage tore it apart and ate the raw flesh. According to one legend, a hunter, after a long tramp, succeeded in catching a rabbit. On his way home he found a smoldering fire which had been started by lightning. Throwing his rabbit on a log, he lay down and went to sleep. When he awoke, he found that his rabbit had fallen into the fire. In attempting to rescue it, the savage got some of the juice of the roasted rabbit on his fingers. By instinct, he put his burnt fingers to his mouth, and the taste was so pleasing that he immediately finished the rabbit, and this is how man learned to cook.
Reduction of metals. Ages later, man began to use fire to make metals and to form them into spears and hatchets for hunting and fighting. The alchemists, as we know, used fire in their attempts to change the base metals into gold, and today fires are burning in many furnaces producing, if not gold, metals of far greater value to the progress of civilization. Copper, bronze, iron, and steel, produced by fire, have been the stepping stones of mans progress through the ages. The chemistry involved in the extraction, purification, and alloying of metals is so interesting and of such great importance that volumes have been written on this subject.
Heating homes. We are so accustomed to living in heated homes that it is only when something goes wrong with the furnace that we give any thought to the blessed fire. To the savage shivering in his cave, however, a fire was a real blessing, even if it did fill his eyes with smoke. Keeping the home fires burning
was a difficult task for the American Indian, who delegated this to his wife. Woe be to the squaw who let the fire go out. In the wintertime, the fire was built on the ground in the center of the tent, which had a small hole in the top to act as a smokestack. Even the palaces of the wealthy in the Middle Ages were cold and damp, the fireplaces being so inefficient that only a portion of one room could be heated at a time. Not until a comparatively recent date were stoves invented, and furnaces were unknown even when your grandfather was a boy.
How fires are started and stopped. You have learned that burning is rapid oxidation which gives off light and heat. In order to start a fire, three conditions are necessary: something to burn; something to support the combustion; and a means of lighting the fuel . Having lived all his life in a home where the furnace is kept burning all winter, the average person seldom thinks of the difficulty of starting a fire.
英语学科八年级上期末复习资料
新目标英语八上1-6单元复习要点
人教新目标版英语八上《Unit 7 How do you make a banana milk shake》word学案2篇
人教新目标版英语八上《Unit 10 I’m going to be a basketball player》word复习教案
人教版[2013版]英语八上Unit 10《If you go to the party》word教案
人教新目标版英语八上《Unit 12 What’s the best radio station》word教案
2012新人教版八上《Unit 2 What’s the matter》word教案1
人教新目标版英语八上《Unit 2 What’s the matter》word教案
人教新目标版英语八上《Unit 12 What’s the best radio station A1》word教案
人教新目标版英语八上《Unit 1 How often do you exercise》word教案
新目标(Go for it)版初中英语八年级上册全册教案-Units 7-8学案
2012新人教版八上《Unit 1 How often do you exercise》word学案
2012新人教版八上《Unit 10 I’m going to be a basketball player》word教案
人教新目标版英语八上《Unit 4 How do you get to school》word学案3篇
人教新目标版英语八上《Unit 3 What are you doing for vacation》word教案
新目标(Go for it)版初中英语八年级上册全册教案-Units 5-6学案
人教新目标版英语八上《Unit 2 What’s the matter》word学案2篇
新目标(Go for it)版初中英语八年级上册全册教案-Units 9-10学案
2012新人教版八上《Unit 2 What’s the matter》word教案
人教新目标版英语八上《Unit 8 How was your school trip》word学案4篇
人教版[2013版]英语八上Unit 1《Where did you go on vacation》(SectionA 3c)word导学案
新目标英语八年级上教学笔记
人教新目标版英语八上《Unit 12 What’s the best radio station A2》word教案
人教新目标版英语八上《Unit 10 I’m going to be a basketball player》word学案2篇
人教新目标版英语八上《Unit 1 How often do you exercise》word学案2篇
新目标(Go for it)版初中英语八年级上册全册教案-Unit 12学案
2012新人教版八上《Unit 10 I m going to be a basketball player》word教案(6课时)
人教新目标版英语八上《Unit 12 What’s the best radio station B2》word教案
新目标(Go for it)版初中英语八年级上册全册教案-Units 1-2学案
新目标(Go for it)版初中英语八年级上册全册教案-Unit 11学案
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |