DANIEL FAHRENHEIT.

Auckland Star, Volume LXVIII, Issue 25, 30 January 1937, Page 5 (Supplement)

DANIEL FAHRENHEIT.

FAMOUS INVENTOR OF THE THERMOMETER

Daniel Gabriel Fahrenheit put his name on a thermometer, and it has parried him to an immortality lasting 200 years and showing yet no sign of fading into obscurity. It was 250 years ago when he was born, May 14, ICBC, in Danzig, and when lie passed on at the age of 50, on September 17, 1736, he was assured of world-wide fame—and never knew it! The world has insisted on remembering him. Reaumer came, and Celsius, who designed the more scientific centigrade thermometer, but it is of old Fahrenheit we think when we speak of the heat wave with 85 degrees in the shade, or 20 degrees below zero in a cold snap. We all know what these figures mean without calculating further. They are just Fahrenheit. If old Daniel Gabriel could come back to the shades of the moon (and the sun) he would be as surprised as pleased. How could he have expected such universal fame ? He had been trained for a merchant, but was caught up in the wave of enthusiasm for science then sweeping over Europe. Galileo had not been long dead, and Isaac Newton had been born in the year his star had set. This was the time when England had established its Royal Society, and Leeuwenlioek had discovered with his microscopes the first bacteria. Science was everywhere, in France and Germany and Holland, and Fahrenheit became a pilgrim to its shrines. He knew Sir Isaac Newton. But he was only a humble attendant in the temple. Not for him were the great discoveries, though in Amsterdam, where he settled, he iningled with the best. He was the handy man iu their laboratories. He made tlie instruments for them to proceed with their measurements, which, as Sir Isaac knew, were the foundation of discovery. He made thermometers, barometers and hygrometers. There were thermometers before his. Galileo had invented one 80 years before, an open tube with liquid in it. Newton had bettered it by employing liquid oil. Halley (of the Comet) had ideas of what a thermometer should be. But until Fahrenheit took the matter in hand the best thermometers were of spirits of wine, and were as untrustworthy as some other products of alcohol. Some makers thought of mercury, but rejected it because it was impure. Fahrenheit had the right idea. He purified the quicksilver, and the first truthful thermometer was born. His mercury did not stick to the tube, or evaporate, or in any other way prove unworthy.

But this promising infant thermometer, destined to be the ancestor of millions of thermometers, had to grow up before science could make nee of it. It had to be graduated. We all know about measuring hotness to-day. But tlien degrees of lieat had to be worked out. A top and bottom temperature had to be found for the thermometer, and in those days ideas about either were rather childish. Some grave men of science had put the bottom degree of cold as that of the coldest day they could remember; but as memories about the weather are generally short, even among the wisest, this was not a very satisfactory standard. The scientists were in better agreement about a standard top temperature, which they fixed on as the body temperature of cattle or deer. But anyone who wanted to graduate a thermometer could not always find a cow at hand, and deer were still harder to come by. Isaac Newton had thought out something more sensible and constant, the temperatures when ice begins to form, and the heat of the human body. Between them was a fixed interval which he divided into twelve degrees. But Fahrenheit improved on even the great Sir Isaac; and here we may note that he must not be thought of merely as a clever instrument maker with a good idea. He did some fine work in experimenting with tempera-

tures, and left it as his little corner stone in tlie temple of science. He found a lower temperature than

and add 32 before we realise that the heat wave is on us with a temperature of 80 degrees Fahrenheit. So old Fahrenheit is still our familiar friend. He was not very successful while he lived, for his dearest invention was a maohine for drying out land, which, would have brought him a fortune in Holland if it had worked. It did not. But he discovered that the boiling point of water varied with atmospheric pressure, and this afterwards proved a starting point in the science of yery low temperatures. And to-day his name Is oftener mentioned than that of any other Empire builder or world wrecker. I —"Children's Newspaper."

freezing water by mixing ice and salt, and that he fixed as the thermometer's zero. He divided the interval between that and body heat as 24 degrees. Then, pushing on, he calculated that water at ordinary atmospheric pressure would boil at 53 degrees on his scale; and presently, for the sake of finer measurement, multiplied his degrees by four. Thus the freezing point of water (or melting point of ice) now became 32 instead of 8; the body temperature became 90, and the boiling point of water became 212. To-day w» put the body temperature about two degrees higher, but Fahrenheit's 32 and 212 have stood the test of centuries. He had his imitators, Reaumer, a Frenchman, whose scheme was to call the freezing point zero and the boiling point 80; and Celsius, the Swedish astronomer, who turned things upside down, calling the boiling point zero and the freezing point 100. Afterwards the French Scientists, seizing eagerly on anything on the decimal scale, adopted Celsius for their own, reversing his thermometer again, and calling it Centigrade. They added a good deal of confusion to our lives, for, though we acknowledge the French logic, we have in Great Britain, and in the United States as well, an oldfashioned attachment to the measures we learned first. When the scientific people tell ua that the temperature is 30 degrees centigrade, we have to multiply by 9, divide by