Sir John Leslie
Sir John Leslie- A Famous Scottish Mathematician, Physicist & Inventor
Sir John Leslie ( 1766-1832 ) John Leslie was born April 10, 1766 in Largo, Fife and is remembered as a mathematician, physicist and inventor. Some documents describe Leslie as a "self-taught mathematician and physicist". His early education was at nearby Leven where he showed an interest, and aptitude, in mathematics and physical science. At the age of 12 he received a gift of mathematical books from the minister of Largo and, at the age of 13, he continued his education at the University of St Andrews, where he completed an arts course. For a short period, until 1787, he studied divinity at Edinburgh University.
Following his formal education he spent some time as a personal tutor (1788-1789) and again, from 1790 to 1804, when he taught the family of Josiah Wedgwood, the famous Staffordshire potter. During his time with the Wedgwood family Leslie travelled extensively in Europe and America but was able to spend some spare time in research and study while also translating the writings of the French naturalist, Georges-Louis Leclerc, Comte de Buffon, which were published in 1793.
Sir John published numerous papers and contributed heavily to Nicholson's Philosophical Journal. He won the Rumford Medal of the Royal Society of London for his "Experimental Inquiry into the Nature and Properties of Heat", published in 1804 and in 1805 he succeeded John Playfair to the Chair of Mathematics at Edinburgh University. His appointment was initially considered controversial, like many of our great thinkers and scientists, he had been accused of heresy, by the Rev. Sir Henry Moncrieff and other members of the synod, for his observations and conclusions which had been based purely on science rather than religion.
The opposition did not deter Leslie from his work which now concentrated on geometry and trigonometry. During his tenure Leslie published two important works on Mathematics; "Elements of Geometry, Geometrical Analysis and Plane Trigonometry" in 1809, and "Geometry of Curve Lines" in 1813.
Leslie was incredibly inventive and, during his intensive investigations, he would make discoveries that enabled the development of new equipment and processes. One of his inventions was the hygrometer, a device for measuring humidity, and this aided him greatly in his discovery of a process of artificial congelation(1810). This process enabled him to create ice artificially with the use of water and mercury. In 1813 he published "A Short Account of Experiments and Instruments depending on the relations of Air to Heat and Moisture".
In 1819 he became Professor of Natural Philosophy at Edinburghand in 1820 he was voted a corresponding member of the Institute of France. In 1823 the first volume of "Elements of Natural Philosophy"was published which, like his earlier work the third volume on geometry "Descriptive Geometry and the Theory of Solids", was never completed. In 1832 he was knighted Sir John Leslie.
Sir John Leslie died on November 3rd, 1832, at Coates, a small property of his near Largo.
Known as the first person to create artificial ice, Sir John Leslie was the inventor of the differencial thermometer which is used for measuring difference in temperature but other inventions include the mentioned hygrometer, the photometer which is used in measuring luminous intensity, the atmometer which is used in measuring the rate of evaporation from a moist surface, the aethrioscope which is used to very accurately measure the variations in temperature due to the condition of the sky and the pyroscope which is a kind of optical thermometer or pyrometer.
John Leslie Links
The Works of Sir John Leslie (1766-1832)
A short, but interesting, biography of Sir John Leslie, by E M Horsburgh, covering areas not mentioned in the above article.
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