2. Passage 4 Do you know who Benjamin Banneker was and what he did? Benjamin Banneker was a self-educated scientist at a time when most African Americans were slaves. Born a free black man in the British Colony of Maryland in 1731， he received some formal education， but he mostly borrowed books and taught himself science and mathematics. At 22， he borrowed a pocket watch， and without any training， figured out how to carve a working wooden clock that chimed each hour. Because of this clock， he became well known and people would visit him just to see his creation. Banneker ran his family farm from many years， but when he was in his late 50s， a neighbor‘s son lent him a telescope. He became interested in astronomy， the study of the planets and stars， and again taught himself a new science. He made calculations of tides， sunrises and sunsets， and even predicted an eclipse. For several years he published an almanac of these calculations. Today， he is best known for publishing six almanacs， called ―Benjamin Banneker‘s Almanac‖ between 1792 and 1797. In the 1790s， Banneker also helped survey and lay out the land for Washington， D. C.， which became the nation‘s capital. For a look at Banneker‘s amazing life， visit the Benjamin Banneker Historical Park & Museum in Ellicott City， Maryland. What subjects did Benjamin teach himself?