compass, In navigation or surveying, the chief device for direction finding on the Earth’s surface. Compasses may operate on magnetic or gyroscopic (see gyroscope) principles or by determining the direction of the Sun or a star. The oldest and most familiar type is the magnetic compass, used in different forms in aircraft, ships, and land vehicles and by surveyors. Magnetic compasses work as they do because the Earth itself is a magnet with a north-south field (see geomagnetic field) that causes freely moving magnets to align themselves with the field.
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James Watt on the steam engine Summary
Among the pleasures to be derived from venturing through the early editions of Britannica is the one we think of as “being present at the creation.” Steam engines had been around as novelties for centuries, but the first practical ones were invented by the Englishmen Thomas Savery in 1698 and
James Watt Summary
James Watt was a Scottish instrument maker and inventor whose steam engine contributed substantially to the Industrial Revolution. Watt was also known for patenting the double-acting engine and an early steam locomotive. He was elected fellow of the Royal Society of London in 1785. (Read James