HERE IS ACCURACY!

Hawera Star, Volume XLV, 6 March 1926, Page 11

HERE IS ACCURACY!

MARVELLOUS MACHINE OF SCIENCE

SCALES WHICH WEIGH A FULL STOP

AS you smoke your cigarette and flick away the paper ash, it. is difficult to believe that a thousand cigarette papers

could not be certain of his longitude within a margin of about 15 miles or so. To-day these instruments are made so accurately that after a journey right round the tvorld they show no greater variation than one second a week, and sometimes .less. , , ■

piled tightly together would measure no more than one. inch high Yet the thickness of a single sheet can be ascertained easily with a Pratt-Whitncy machine, that will measure with perfect accuracy things even one hundred times thinner than a cigarette paper. By its aid you can discover the exact thickness of a house fly’s wing—accurate to one-two-hundred-thousandth pai-t of an inch. To find out the diameter of a hair from your head is quite clumsy work for a machine of such delicacy, and it might surprise many people to know that a thousand human hairs of ordinary texture, laid side by side as closely as possible, barely stretch an inch. Thousand of tiny particles called corpuscles float about in your blood. They can only be seen under the strongest microscope. But an amazing machine has been invented by which it is possible to cut a blood corpuscle into three equal parts With this machine you can cut a piece of cheese measuring one inch in each direction into twelve thousand .slices, and thus make a monster sandwich, for the cheese would then cover completely a piece of bread ten feet long and eight feet wide.

More Avonderful still is an invention of Mr W. Duddell, by means of which the heat, of .the stars can be registered. Light from the nearest stars, travelling at a speed of 186,000 miles per second, takes many years to reach us, yet the Avarmth these, far-off bodies give to the earth has been measured. So delicate is the instrument that' it Avill eAan measure the heat from your hand if you hold it fen feet from the instrument. ’ -Other marvellous machines been deA'ised to Aveigh the stars. Moving at the rate of one inch every hundred years, Avhich seems almost indetectable, the change in position of “faults” in-coal and other mines can be forecast Avith astounding accuracy. An instrument called a cupmicromoter does this, and is so sensit-iveT that it can also cheek the leakage from a huge water reservoir. eA’eu though it amounts to no more than one bucketful in a night. IlaA'e you eA r er AA T ondered hoA\ r the lenses of your spectacles are ground so accurately? An instrument called a spherometer is used for detected errors in the curyature of lenses, and is able to register Animations as small as one-hundred-thousandth part of an inch. Most astounding of all modern mechanical marvels.are the scales so exquiistely balanced that it is possible by their aid to Aveigh things Avhich you would think liaA’e no weight at all. If you place a piece of paper in one pan of the scales, for instance, and an equal weight in the other, the beam Avill tip decisively if .you mark a full-stop in pencil on the piece of paper.

No less astonishing is an instrument constructed by Lord Blythswood that is used by engineers for drawing parallel lines nearer to one another than you can imagine. On the edge of a sixpence this remarkable machine can draw nearly one hundred separate parallel lines.

Time-measuring instruments have now attained extraordinary perfection. Some years ago, even the finest chronometers could not be relied upon implicitly, and after travelling for a few Aveeks from land the captain of a ship.