| In many ways, the automobile has been one of the most important inventions of the modern age. |
| People have been able to travel much more freely, |
| and across much greater distances, than was possible in the past. |
| The automobile, which most people refer to as the “car” |
| has also had some harmful consequences, such as pollution and accidents. |
| However, it is clear that life has changed profoundly as a result of the car. |
| Modern cars are very complicated, but the basic idea of how a car works can be described briefly. |
| When the keys are turned in the ignition of the car, |
| this creates a spark that ignites some gasoline vapor inside a cylinder. |
| Then, the rapid expansion of this vapor pushes against a part called a piston. |
| The movement of the piston then causes a turning motion in a shaft that is connected to the wheels. |
| The wheels turn, and the car moves. |
| The invention of the car, and the engines used by cars, |
| happened gradually in the late nineteenth century, mainly in France and Germany. |
| In the early twentieth century, an American engineer named Henry Ford developed a new way of making cars. |
| Instead of having one worker produce an entire car, |
| he had each worker perform one part of the production of many different cars. |
| This system was very efficient and allowed the mass production of cars. |
| The first car to be produced in large numbers was called the “Model T”. |
| The Model T Ford and other cars that were soon produced in large numbers |
| were cheap enough that many people could afford to buy them. |
| Many new roads were built and paved throughout North America to allow cars to be driven from town to town. |
| People were able to travel much more easily and to visit places that had previously been difficult to reach. |
| Some problems also came with the widespread use of cars. |
| One of these problems was air pollution, because car engines burn gasoline, |
| which produces poisonous exhaust fumes. |
| Gradually, new laws and new technology have led to reductions in the air pollution that is caused by cars. |
| Moreover, cars today are much more “fuel efficient” than they were in the past, |
| requiring less gasoline to travel a given distance. |
| However, this pollution is still a problem because of the many millions of cars that are used each day. |
| Another problem has been car accidents, which have caused many thousands of deaths each year. |
| During the 1960s, some journalists brought attention to the unsafe features of many cars. |
| As a result, the safety of cars has been greatly improved. |
| In addition, the use of seat belts is now required by law. |
| However, car accidents continue to be a serious problem. |
| The future is likely to bring many interesting new changes to the car. |
| Improvements in the safety of cars, in fuel efficiency, |
| and in the cleanliness of car emissions are continuing to be made. |
| Also, the increasing use of the car in economically developing countries will probably have important effects upon people’s lives around the world. |
