| A | B |
|---|
| petroleum | An oily liquid. In 1855, a chemist reported that kerosene could be made more cheaply from petroleum. |
| patent | A government document giving an inventor the exclusive right to make and sell his or her invention for a specific number of years. |
| business cycle | The good and bad times of business. |
| Booms | The good times of business when people buy more and some invest in business. As a result, industries and business grow. |
| Busts | The bad times of business. Spending and investing decrease. Industries lay offworkers and make fewer goods. A depression may result. |
| Bessemer steel process | A new manufacturing technique that used less than one-seventh of the coal that was used to make steel. William Kelly in the US and Henry Bessemer in England independently developed this new process. |
| generator | A machine that produces electric current. |
| Thomas Edison | The inventor who found the most ways to use electricity. In 1876, he opened a laboratory in Menlo Park, New Jersey. He invented a safe steady light bulb, the phonograph and a moving-picture viewer. |
| Alexander Graham Bell | A Scottish immigrant who taught deaf students and invented the telephone. |
| Centennial Exhibition | A show in Philadelphia that was held in 1876 in Philadelphia to celebrate the 100th birthday of America. Bell showed his telephone here and amazed several of the world's leading scientist. |
| transcontinental railroad | A railroad that spanned across the whole continent. |
| standard time | A system that divided the United States into four time zones. |
