URL：http://upload.wikimedia.org/wikipedia/commons/thumb/9/90/Trevithick_High_Pressure_Steam_Engine_-_Project_Gutenberg_eText_14041.png/220px-Trevithick_High_Pressure_Steam_Engine_-_Project_Gutenberg_eText_14041.png
掲載元：http://ja.wikipedia.org/wiki/リチャード・トレビシック
