The magnetic compass is an old Chinese invention, probably first made in China during the Qin dynasty (221-206 B.C.). Chinese fortune tellers used lodestones (a mineral composed of an iron oxide which aligns itself in a north-south direction) to construct their fortune telling boards.
Guide to Pennsylvania weather in April. The average maximum daytime temperature in Pennsylvania in April is a comfortable 17Â°C (63Â°F). The average night-time temperature is usually a cold 5Â°C (41Â°F). There are usually 7 hours of bright sunshine each day, which represents 55% of the 13 hours of daylight. Expect 95mm (3.7 inches) of rainfall across the whole of April with 11 days with some rain falling.
At a glance: average April temperatures for the top 10 tourist destinations in the United States (High/ Low): 1  New York City: 60Â°F / 45Â°F (15Â°C / 7Â°C) 2  Los Angeles: 71Â°F / 54Â°F (22Â°C / 12Â°C) 3  Chicago: 57Â°F / 39Â°F (14Â°C / 4Â°C) 4  Washington, DC: 66Â°F / 42Â°F (18Â°C / 7Â°C) 5  Las Vegas: 69Â°F / 44Â°F (20Â°C / 6Â°C) 6  San Francisco: 63Â°F / 49Â°F (17Â°C / 9Â°C)