GAINED FAME BY DEGREES

Evening Star, Issue 22572, 13 February 1937, Page 11

GAINED FAME BY DEGREES

BUT BECAME A SYMBOL THE ROMANCE OF THE THERMOMETER- • AND FAHRENHEIT Daniel Gabriel Fahrenheit, who gave the world the mercury thermometer and the system by which it measures heat and cold, was born 250 years ago and died 200 years ago. Although his name is an international symbol—“ m° re often mentioned than that of an Em-pire-builder supplying the news in a heat wave or in a frost”—only tho scientists marked the bicentenary of his passing. ' . Summer at last had shouldered its way in, and the sky had that windscrubbed, rain-washed clarity which suggests always that there is furnace heat to come (writes Gordon Williams, in the Melbourne ‘Argus’). I turned to the physicist, who, as a sideline, practises a desultory astrologv. “ What exactly is the temperature. He glanced at the thermometers on his walls. . . , “ Precisely,” he said—and I thina ho has a monopoly on precision, except in his astrological activity—“ it is 30deg centigrade and 86deg Fahrenheit.” “ Making in all 116 deg, I commented facetiously. “At any rate, what are these degrees _ all about i Who, for instance, said it had to be blistering hot at 96 and perishing cold at 28?” „ , 1 was sorry the moment I had spolien. Once start the physicist, and he becomes afflicted with a creeping palpitation of the tongue. Add to this his belief that in some fashion the mantle of Ray Lankaster has fallen on his shoulders, and the fact that he and vocal self-expression are closer together than half-past 6, and you will guess what I had begun. “ We have just ended the < bicentenary, year of the death of Daniel Gabriel Fahrenheit, and you ask me that! It is just 200 years since a man put ms name on a thermometer, which has carried him to immortality ” “By degrees,” I interjected, to stop the spate. But he was as unconquerable as chewing gum. He swept on, unrelentingly, in a frenzy of sesquipedalianism. - . “ - —-and you ask mo that I Know then that temperature is measured in terms of an arbitrary scale of temperature, that the Fahrenheit scale servos in everyday use engineering and medicine, and that the centigrade scale is used for scientific purposes; know, then, that ”■ On and on . v . Still, in the tale of Fahrenheit, as he failed to tell it, there is a fascinating story. Only scientists seem to be aware of the story of the man who is our familiar friend, who stays with us through heat wave and hoar frost, and who thinks nought of zero and remains calm at boiling point, deserves better of us. Particularly does he deserve well of Melbourne, where the thermometer, recording the illimitable variations through which we move, must yearn to plant its bulb and wait fertile growth of a 40-hour meteorological week.

But I learned a little from 1 tlie physicist.. Daniel Gabriel Fahrenheit first saw: the light in Danzig in 1686; arid, fraying measured the heat which that light can bring, passed on in 1736, having set his own little cornerstone in. the temple of science, and leaving the world a measurably 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 is who has given us the figures that tell the story. He was born into a world which was in the boom days of science. Europe then was in a scientific furore. England had established its famous Royal Society. _lsaao_ Newton was watching and drawing his own conclusions from another fall connected with an apple. Everyhere there was a probing and a theorising, and the discovery of bacteria by Leeuwenhoek with his microscopes was part of the germ in 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 Fahrenheit's shutters down when the scientific spring came. He drank deep at the fourtain, and soon we find him acting as a humble attendant in the laboratori® of the great, making hygrobarometers, thermometers, and othei instruments—probaly he would have made gasometers had he thought of tint n —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 vent more smoothly for the lubricant. But until Fahrenheit bore down on the problem the most reliable measu’es employed spirits of wine, with somewhat alcoholic results. Then came one wio tried mercury, but found its impurhy forbidding. Fahrenheit purified tin mercury—and there was horn the first really trustworthy heat measun, the descendants of which today mqv be seen staring placidly from walls, mors, and ceilings, in a hundred differeni guises from Land’s End to Labrador, and from Nothor Wallop to Pakonhim Upper. Still, ;hat was not the end of the process. Tie degrees of freat still had to be ficed—the degrees by -which today whai someone says, ‘ It’s 94,” we know inmediately that it is a time for beaches and internal irrigation, and “ It’s 4S” makes ns wonder whether the potalo seeding should have been delayed i few weeks. In a word, a “top” md a “bottom” temperature had to befound before the thermometer could tellits tale, and if it had not been for Fahreiheit we might still have been gauging fro standard top temperature by the belt of a cow’s body! Many {have and ' earnest men of science vbre exercised about these standards bf high and low, and many put the blttom degree of frigidity as that of thl coldest day they could remember. But memory is short, and memories ’ary, and anything might have happfred. There was little unanimity—fer how could the recollection of a gentlenan from Spitsbergen agree with that ola gentleman from Alcatraz on such a lice point? The _ “ top” standard fared better, the scientist of the day deciding that they would lieasure it by the body temperature of lattle or deer. But as one learned writir phrases it, anyone who wanted to graduate a thermometer could not aWays find a cow in his laboratory; md it was even more difficult to pass the buck to a deer. It remained forjlsaac Newton, with becoming graviy, to point out certain fundamental jrrors in the procedure, and he fixed! 1 low” at the temperature at whicfrice begins to form, and “high” at fie heat of the human body. The iiterval he divided into 12deg. Then f’ahrenheit imeroved on

the great Sir Isaac.—lie _ found a still lower temperature by mixing ice with salt, and fixed that as his zero. The interval between that and body heat he divided by 24deg. Continuing his experiments, he found that water at ordinary atmospheric pressure would boil at 53deg 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. Everything was pleasantly simple until Celsius, the Swedish astronomer, inverted the whole measuring system, calling the boiling point zero, and the freezing point 100. Later French scientists, with typical Gallic enthusiasm and bonhomie, reinverted Celsius and adopted him—ho was a heaven-sent gift to the decimalists—and called his thermometer centigrade. Now, when the physicist persists in telling me that it is 30deg centigrade, I have to multiply the number by 9, divide by 5, and add 32 before I can express myself in terms of Fahrenheit and disgust. Two hundred years since he died—and a passing world gazes heedlessly on his monuments in city streets and country homes, mops, listlessly, a collective, damp brow, and takes it for granted. If they had been left to chase a cow over a sun-baked paddock before they could state their curiosity about the day’s heat, they might be more grateful for Fahrenheit’s work. . . . “ Fahrenheit,” the physicist was droning, “ was not very successful while he lived. His dearest invention was a machine for drying out land, which would have made Him immensely rich in Holland—if it had worked. We remember him with gratitude because he revealed that the boiling 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. As I write, summer has returned to the lap of winter, lingering so long there that it is causing a great deal of gossip, and tho temperature is on everyone’s tongue. There is paradox in it, for Fahrenheit is sung as no hero, yet remains everyone s zero.