GAINED FAME BY DEGREES

Greymouth Evening Star, 20 February 1937, Page 12

GAINED FAME BY DEGREES

romance of thermometer. 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—“more often mentioned than that of an Empire-builder supplying the news in a‘heat wave or in a frost’only the scientists marked the bicentenary of his passing. Summer at last hau 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 astrology. ■ “What exactly is the temperature? He glanced at the thermometers on his walls. “Precisely,” he said —and I think he has a monopoly on precision, except in his astrological activity—“it is 30deg. centigrade and 86deg. Fahrenheit.” “Making in all HGdeg.,” I commented facetiously. “At any rate/ what are these degrees all about? Who, for instance, said it had to be blistering hot at 96 and perishing cold at 28?”

I was sorry the moment I had spoken. 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 ybii ask me. that! It is just 200 years since a man put his 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 me that! Know then that temperature is measured in terms of an arbitrary scale of temperature, that the Fahrenheit scale serves in everyday use engineering and medicine, and that the centigrade scale is used for scientific purposes; know, then, that ” On and on . . .

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 isour familiar friend’, who stays with us thrdugh heat wave and hoar frost, and who thinks nought of zero and rertiains 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 waitfOr the growth of a 40-hour meteorological week. But I learned a little from the physicist.

FAHRENHEIT’S CAREER. Daniel Gabriel Fahrenheit first saw the light in Danzig in 1686, and, having 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. Eng-’ land had established its famous Royal’ Society. Isaac Newton was watching and drawing his own conclusions from another fall connected with an apple. Everywhere there was a probing and theorising, and the discovery of bacteria by Leeuhienlioek 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 fountain, and soon we find him acting as a humble attendant ia the laboratories Of the great, making hygrometers, barometers, thermometers, and other instruments —probably he would have made gaosiiieters 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 until Fohrenheit bore down on the problem the most reliable measures employed spirits of wine, with somewhat alcoholic results. Then came one who tried mercury—and there was born the first really trustworthy heat measure, the descendants of which to-day may be seen staring placidly from walls, floors, and ceilings, in a hundred different guises from Land’s End to Labrador, and from Nether Wallop to Pakenham Upper. Still, that was not the end’ of the process. The degrees of heat still had to bo fixed—the degrees by which today when someone says “It’s 94,” we know immediately that it is a time for Leaches and internal irrigation, and “It’s 43” makes us wonder whether the potato seeding should have been delayed a few weeks. In a word, a “top” and a, “bottom” temperature iiad to be found before 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!

DISPUTED STANDARDS. Many grave and earnest, men o£ 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 that of a gentleman from Alcatraz-on such a nice point? The “top” standard fared better,l the scientists n“ the day fl-widinc that they would measure it by the body ( temperature of cattle or deer. But as.

one learneid writer phrases it, anyone who wanted to graduate- thermometer could not always find a cowin his. laboratory ; and It- )yas even more difficult to pass the buck to a deer, it repiained fb'r Tsaac Newton, with becoming gravity,’ to -'point out certain fundamental errors in tlie -prbccdtire, and lie fixed “loW” at/the temperature at which ice begins to form, and "high” At the iie’d-t outlie ‘human, .body. The interval, he divided into 12deg. Then Fahrenheit improved on.; the great Sir -Isaac—lie’ Jfoutfd a still lower temperature by iriixihg ’ice with salt, and fixed that as 'his zero. The. interval between that and body heat he divided .by 24cleg. his experiments, he found that water at ordinary atmosplidfic ‘pressure would boil at 53deg, on bis scdle; ’then, to get a more precise measure, dife multiplied all his degrees by four. Thus the freezing point of water became 32 instead’ bf 8, the body temperature 56, and foiling point '2l'2. Tb-clay body heat is- 98.4, bu,t Fahrenheit’s other measuhes have remained 'with us., -'Everything/was simple until Celsius, the Swedish astronomer, inverted the whole measuring system,, calling the boiling poirit zero, and the freezing point 100. x 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 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 the temperature is on everyone's tongue.. There is paradox in it, for Fahrenheit is sung as no hero, yet remains everyone’s zero.