Story of Daniel Gabriel Fahrenheit

Hawke's Bay Herald-Tribune, Issue 27, 16 February 1937, Page 15

Story of Daniel Gabriel Fahrenheit

J^ANIEL GABRIEL FAHRENHEIT, who gave the world the mercury thermometer and. the system by whlch it measures heat and cold, was born 250 years ago apd died 200 years ago (writes Gordon Willlams ln the Melbourne Argus) . Although his name ls an international symbol — "more often mtentioned than that of an Emplre bullder supplying the news ln a heatwave or In a frost"— only the sclentlsts marked the blcentenary of his passing. I Daniel Qabriei Fahrenheit flrst saw tha light in Danzig in 1686, and, having measured the heat whlch that light. can bring, passed on Izi 1736, having set his own little corner-stone in the temple of science, and leaving the world a mewurably better place than he found it. Reamur came after him in 1731, Celsius brought his centigrade thermometer in 1742, but Daniel Gabriel is the one who is the news in the heat wave or in the frost. He it ls who has given us the flgures that tell the story. • • * TTE was born lnto a world whlch was in the boom days of science. Europe then was in a scientic furore. England had established its famous Royal Society. Isaac Newton was watching and drawing his own conclusions from another fall connected with an apple. Every where there was a problng and a theorising, and the discovery of bacteria by Leeuwenhoek with his micrpscopes was part of the germ ln all this yeast. Daniel. was trained to be a merchant, to buy and sell, to scale and measure, to haggle and huckster. But, even as it is impossible . to keep a good thermometer up when winter comes, so it was impossible to keep Fahrenhelt's shutters down when the scientiflc spring came. Work In Laboratorles. TTE drank deep at the fountain, and so we find him" acting as a humble attendant in the laboratorles of the great, making hygrometers, barometers, thermometers, and other Instruments — probably he would have made gasometers had he thought of them— with which the greater brains laid their foundations of discovery. Galileo had, 80 years earlier, made a thermometer, a kind of open tube with- a liqUid in it.. Newton substituted oil, with better results. Heat measurement went more smoothly for the lubricant. But unth Fahrenheit bore down on the problem the most reliable measures employed spirits of wine, with somewhat alcoholic results. Then came one who trled mercury, but found its impurlty forbidding. • • • TfAHRENHKlT purified the mercury — and there was born the flrst really trust worthj heat measure, the descendants of which to-day may be seen staring placidly from walls, floors and ceilings in a hundred different gulses, from Land's End to Labrador, and from Nether Wallop to Pakenham Upper. Still, that was not the end of the proeess. The degrees of heat stiil had to be flxed— the degrees by which to-day when someone ijays, "It's 94," we know ; immediately that it is a tlme for beaches • and internal irrigation, and "tt's 43" makes us wonder whether the potato i seeding should have beeh delayed a few weeks. In a word, a "top" and a "bot- : tom" temperature had to be found bfefore :

the thermometer could tell its tale, and if it had not been for Fahrenheit we might still have been gauging the standard top temperature by the heat of a cow's body! Many grave and earnest men of science were exercised about these standards of high and low, and many put the bottom degree of frigidity as that of the coldest day they could remember. But memory is short, and memories vary, and anything might have happened. There was little unanimity — for how could the recollection of a gentleman from Spitzbergen agree with tbit oi a gentleman from Alcatraz on such a nice point? The . "top" standard fared better, the scientists of the day deciding that they would measure it by the body temperature of cattle' or deer. But as one learned writer phases it, anyone who wanted to graduate a thermometer- could not always find a cow in his laboratory; and it was even more difficult to pass the buck to a deer. Newton Folnts Way. TT remained for Isaac Newton, with beA coming gravity. to point out certain fundamental errors in the procedure, and he flxed "low" at the temperature at Which ice begins to form and "high" at the heat of the human body. The interval he divided into 12 degrees. Then Fahrenheit improved on the great Sir Isaac — he found a still lower temeprature by mlxing ice with salt, and flxed that as his zero. The interval between that and body heat he divided by 24 degrees. Continuing his experiments, he found that water at ordinary atmospheric pressure would boll at 53 degrees on his scale; then, to get a more precise measure, he multiplied all his degrees by four. Thus the freezing point of water became 32 instead of 8, the body temperature 96, and boiling point 212. To-day body heat is 98.4, but Fahrenheit's other measures have remained with us. Centigrade. J^VERYTHING was pleasantly simple until Celsius, .the Swedish astronomer, inyerted the whole measuring system, . cailing the boiling point zero, and the freezing point 100. Later, French scientists, with typical Gallic enthusiasm and bonhomie, reinverted Celsius and adopted him — he was a heaven-sent gift to the decimalists — and called his thermometer centigrade. Now, when the Physicist persists in telling me that it is 30 degrees centigrade, I have to multiply the number by 9, divide by 5, and add 32 before I can express myself in terms of Fahreinheit and disgust. Two hundred years slnce he died — and a passing world gazes heedlessly on his monumepts in clty streets and country homes, mops, listlessly, a collective, damp brow, and takes it for granted. Fahrenheit was not very successful while he lived. His dearest invention was a machine for drying out land, whlch would have made him immensely rich in Holland— if it had worked. We remember him with gratitude bcause he revealed that the boilipg point of water varied with atmospheric pressure, and this proved a starting place in the science of very low temperatures. ' Fahrenheit — almost forgotten, save as a symbol, by all of us who profess not science. There is paradox in it, for Fahrenheit is sung as no hero, yet remains everyone's zero.