In 1486 Diaz was appointed by King John to lead an expedition whose main purpose was to find the country of the mythical Christian African king known as Prester John.
www link :
The legend of Prester John

Diaz sailed first towards the mouth of the Congo, then following the African coast, he lost sight of the coast and was driven by a violent storm, far beyond the cape to the south.

Eventually he turned northward and reached the southern tip of Africa, which King John, in view of the success of the expedition named the Cape of Good Hope.

In 1488 Diaz returned after an absence of more than sixteen months. He had shown the way to Vasco da Gama whom in 1497 he accompanied as far as the Cape Verde Islands.

www link :
Diaz Page




































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Drake, Sir Francis
1540-1596



English navigator who cirgum-navigated the world, and played an important role in the defeat of the Spanish Armada.

In 1577, Francis Drake left England with five ships, crossing the Atlantic to the South American coast. After disposing two unfit ships he sailed through Strait of Magellan into the Pacific where one more ship got lost and another returned back to England in disgrace.

For almost a year Drake raided and plundered Spanish settlements all along the coast up to Mexico. Sailing deep into the Pacific he turned east again and followed the coast up to Oregon and Washington. Then he crossed the Pacific and Indian Oceans, rounded the Cape of Good Hope into the Atlantic, sailed up the coast of Africa, and arrived back in England in the fall of 1580, after nearly three years.

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Biography































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Euler, Leonhard
1707-1783


Swiss born Euler was the most prolific mathematician of all time and he did for modern analytic geometry and trigonometry what the 'Elements' of Euclid had done for ancient geometry.

He spent most of his life in Berlin and St. Petersburg. He did much of his work after he became blind in one eye in 1735 and totally blind in 1766.

Euler contributed new ideas in calculus, geometry, algebra, probability, and number theory.
He also worked in many areas of applied mathematics, such as acoustics, optics, mechanics, astronomy, artillery & navigation.

See a mathematical demonstration of  Euler's genius

www link :
From the University of St. Andrews, Scotland
Euler biography




































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Fahrenheit, Gabriel Daniel
1686-1736


German physicist, who was born in Poland, but after 1701 lived in Amsterdam. He invented the mercury thermometer and introduced the Fahrenheit scale, still used in the U.S. today.

Fahrenheit used body temperature (90°F) and ice/salt (0°F) as fixed reference points, with the freezing point of water awarded a value of 30° (later revised to 32°).

Using his thermometer, Fahrenheit was able to determine the boiling points of liquids and show that liquids other than water also had fixed boiling points that varied with atmospheric pressure.

www link :
Biography