Source: Dainik Bhaskar (01-April-2018)
Benjamin Franklin FRS FRSE (January 17, 1706 [O.S. January 6, 1705] – April 17, 1790) was an American polymath and one of the Founding Fathers of the United States. Franklin was a leading author, printer, political theorist, politician, freemason, postmaster, scientist, inventor, humorist, civic activist, statesman, and diplomat. As a scientist, he was a major figure in the American Enlightenment and the history of physics for his discoveries and theories regarding electricity. As an inventor, he is known for the lightning rod, bifocals, and the Franklin stove, among other inventions. He founded many civic organizations, including the Library Company, Philadelphia’s first fire department and the University of Pennsylvania. Franklin earned the title of “The First American” for his early and indefatigable campaigning for colonial unity, initially as an author and spokesman in London for several colonies.
Inventions and scientific inquiries
Franklin was a prodigious inventor. Among his many creations were the lightning rod, glass harmonica Franklin stove, bifocal glasses and the flexible urinary catheter. Franklin never patented his inventions; in his autobiography he wrote, “as we enjoy great advantages from the inventions of others, we should be glad of an opportunity to serve others by any invention of ours; and this we should do freely and generously.”
Franklin started exploring the phenomenon of electricity in 1746 when he saw some of Archibald Spencer’s lectures using static electricity for illustrations. In recognition of his work with electricity, Franklin received the Royal Society’s Copley Medal in 1753, and in 1756 he became one of the few 18th-century Americans elected as a Fellow of the Society.
Franklin was also a pioneer in the study of slave demography, as shown in his 1755 essay.
Atlantic Ocean currents
Franklin published his Gulf Stream chart in 1770 in England, where it was completely ignored. Subsequent versions were printed in France in 1778 and the U.S. in 1786. The British edition of the chart, which was the original, was so thoroughly ignored that everyone assumed it was lost forever until Phil Richardson, a Woods Hole oceanographer and Gulf Stream expert, discovered it in the Bibliothèque Nationale in Paris in 1980.
Wave theory of light
Franklin was, along with his contemporary Leonhard Euler, the only major scientist who supported Christiaan Huygens’s wave theory of light, which was basically ignored by the rest of the scientific community. In the 18th century Newton’s corpuscular theory was held to be true; only after Young’s well-known slit experiment in 1803 were most scientists persuaded to believe Huygens’s theory.
On October 21, 1743, according to popular myth, a storm moving from the southwest denied Franklin the opportunity of witnessing a lunar eclipse. After the Icelandic volcanic eruption of Laki in 1783, and the subsequent harsh European winter of 1784, Franklin made observations connecting the causal nature of these two separate events. He wrote about them in a lecture series.
Though Benjamin Franklin has been most noted kite-wise with his lightning experiments, he has also been noted by many for his using kites to pull humans and ships across waterways. The George Pocock in the book A TREATISE on The Aeropleustic Art, or Navigation in the Air, by means of Kites, or Buoyant Sails noted being inspired by Benjamin Franklin’s traction of his body by kite power across a waterway. In his later years he suggested using the technique for pulling ships.
Concept of cooling
Franklin noted a principle of refrigeration by observing that on a very hot day, he stayed cooler in a wet shirt in a breeze than he did in a dry one. To understand this phenomenon more clearly Franklin conducted experiments. In 1758 on a warm day in Cambridge, England, Franklin and fellow scientist John Hadley experimented by continually wetting the ball of a mercury thermometer with ether and using bellows to evaporate the ether.
Temperature’s effect on electrical conductivity
According to Michael Faraday, Franklin’s experiments on the non-conduction of ice are worth mentioning, although the law of the general effect of liquefaction on electrolytes is not attributed to Franklin.
An aging Franklin accumulated all his oceanographic findings in Maritime Observations, published by the Philosophical Society’s transactions in 1786. It contained ideas for sea anchors, catamaran hulls, watertight compartments, shipboard lightning rods and a soup bowl designed to stay stable in stormy weather
In a 1772 letter to Joseph Priestley, Franklin lays out the earliest known description of the Pro & Con list, a common decision-making technique, now sometimes called a decisional balance sheet.
Oil on water
While traveling on a ship, Franklin had observed that the wake of a ship was diminished when the cooks scuttled their greasy water. He studied the effects on a large pond in Clapham Common, London.
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