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Feature Article: Way To Go...
The pole star was
recognized by the ancients as being a constant reference for determining
direction. The Norsemen in the 11th century used a needle of magnetic
iron inserted in a straw and floated on water to point to the
pole star. Petrus Peregrinus de Maricourt invented the pivoted
floating compass with lubberline and sight for bearing. The modern
compass is little more than one-hundred years old.. Deviation was written about in 1627 by John Smith as a problem encountered through use of metal nails in his compass box. Captain. Matthew Flinders in 1.801-2 found way to correct by use of "Flinder's Bars as did Lord Kelvin through use of Kelvin spheres. Placement of soft iron spheres at sides of compass could be used to correct deviation. The development of the gyro compass began in 1851 when Leon
Foucault used suspended cannon shot on a long wire pendulum to
show the rotation of the earth as well as the inertia of the free
swinging ball. By 1852 he had created the gyroscope but had trouble
applying continuous power. By 1900 the electric gyroscope was
invented by both Elmer A. Sperry and Anschutz-Kampfe of Germany.
By 1911 gyro compasses were in use soon to be followed by gyro
repeaters (selysn(sp) units) and gyro pilots. First airborne gyroscopic
instruments were tried on airships. |
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