302 



TRANSPOR T ATI ON 



WHAT YOU SHOULD AIM TO ACQUIRE FROM 

 THIS STUDY 



1. An understanding of the method of construction 



of macadam and cement roads. 

 2 An understanding of the following things about 



the automobile : 



The principles involved in the power system. 



The principle of the clutch and transmission. 



The principle of the fuel system. 



The principle of the differential. 



3. A knowledge of the importance and development 

 of railroads in the United States. 



4. A knowledge of how electricity is used in land 

 transportation. 



5. The importance of the bus in transportation. 



TEST OF MASTERY OF THE TOPIC 



In your notebook complete the statements, answer the 

 questions, and comply with the instructions. 



1. The steel framework upon which the automobile is 

 built is called the . . 



2. In the carburetor of the automobile fuel is changed 



to : and mixed with _ 



3. When the carburetor is "choked" . 



. is shut out. 



4. The valve in the carburetor which keeps the level 

 of liquid gasoline always the same is the . valve. 



5. What happens when the carburetor is flooded? 



6. A voltage electric current is necessary to make a 



spark jump across a spark plug. 



7. The power stroke of the automobile follows the 



stroke and is followed by the stroke. 



8. What is the clutch and what does it do in the opera- 

 tion of the car? 



9. The transmission of an automobile is made up of 



Explain what it is used for. 



10. The differential of an automobile is located It 



enables 



11. Explain how macadam roads are built. 



12. Why are cement roads superior to macadam roads ? 



13. moves back and forth in the cylinder of a steam 



engine. 



14. Steam enters the cylinder of a steam engine from the 

 through openings. 



15. The slide valve moves back and forth in the of 



the steam engine. 



16. When one part of the steam engine cylinder is re- 

 ceiving live steam the other side of the piston is con- 

 nected to the - 



17. Write a paragraph on the importance of the railroads 

 in the development of the country. 



18. Some of the earfy locomotives constructed in this 

 country were named 



19. Trains, electric cars, and many buses are stopped by 

 means of brakes. 



20. Write a paragraph on the advantages of bus travel. 



21. Trolley cars are run by electric . 



22. Electric current from a trolley car gets back to the 

 generating station through the and the 



23. Write a paragraph on the advantages and disad- 

 vantages of the electric locomotive. 



24. A recent development in automobiles, buses, and trains 

 that has tended to increase their speed and decrease fuel 

 consumption is known as 



25. Another improvement in trains that has also tended 

 to increase their speed is the use of in their construc- 

 tion. 



TOPIC 2. TRAVEL ON WATER 



SUGGESTED PROBLEMS AND QUESTIONS 



1. What is the history of transportation by 

 water? 



2. Why do some substances float and others 

 sink? 



3. What is stability and what are the factors 

 that affect it? 



4. How are modern ships propelled? 



5. How are submarines enabled to sink and rise 

 in water? 



SUGGESTIONS AND HELPS FOR STUDY 



1. Read the problems and questions carefully be- 

 fore you try to solve them. It is quite likely that most 

 of your information for this topic will have to be ob- 

 tained from textbooks. If, however, you have the 

 opportunity to inspect any types of boats, do so and 

 gather all the first-hand information that you can. 



2. Examine carefully all the pictures and diagrams 



given in this textbook and others in connection with 

 methods of water transportation. They will help you 

 understand the principles involved in water trans- 

 portation. 



3. Study the following words and definitions. They 

 will help you in understanding this topic. 



stability the state of being firm or steady, so as not to 

 be easily tipped over. 



buoyancy- a force supporting a floating body. 



gravity the pull of the earth upon objects. 



ballast any heavy substance put into the hold of a ves- 

 sel to make it stable. 



EXPERIMENTS OR DEMONSTRATIONS WHICH WILL 

 HELP ANSWER THE PROBLEM QUESTIONS' 



Experiment 177. Why does a boat, made of a sub- 

 stance heavier than water, float? 



Roll a piece of lead foil into a ball and place it in water. 

 Why does it sink? Now unroll the ball of lead foil and 



'See workbook, p. 109. 



