The Great Science of Weighing.

Kaipara and Waitemata Echo, 18 September 1914, Page 2

The Great Science of Weighing.

The art of weighing has expanded into a compreherasive science and can no longer be called a mere art. Scales are made of metal, but the set herein described is not made of anything. Scales are in hourly use that can weigh a pencil-mark whose length is one-fourth of an inch; or a section of a hair of equal length. The usual practice fn weighing runs from grains, ounces, pounds, up to tons, usually one ton, and then up to fifty or more tons in railroad weighing, costing hundreds and thousands of pounds.

But humans would find it quite difficult to make scales that would weigh millions, billions, trillions, quadrillions, quintillions-, sextillions septillions, octillions, and nonillions of tons, or decillions. An instrument able to weigh a decillion tons can now be purchased for a halfpenny—a pencil. The scales are not made of metal ; instead, a set and fixed specific speed is the next to all-powerful engine used. But it

is far more easy to run a locomotive or steamship without knowing a single law of these complex machines than to even attempt to use the speed-scales without knowing every minute detail of every velocity law of moving bodies.

Let a tram-car start from rest and keep moving faster and faster until its rate of motion is, say, twenty miles per hour at the end of one minute. If the speed of the car increased uniformly during the entire minute its average speed is ten miles per hour, because it started from rest and-increased to twenty miles per hour. If a body moves during one minute at twenty miles per hour, the distance traversed will be speed multiplied by time, or

twenty miles multiplied by one-six-tieth of an hour, or one-third of a mile ; but the average speed in the case of the car is ten miles per hour, so that the distance moved over is half as great or one-sixth mile. This is a fundamental law of nature and is of enormous importance.

Law ; For uniformly increasing speed, starting from rest, the velocity increases with the time, but the distance traversed is that moved over by the moving body with its average speed, or one-half.

If measuring the distance fallen through by a body let fall at the rigidly exact beginning of one second of time, to the rigidly exact end thereof, is difficult, what shall be said of finding how fast it is falling at the end of the second. Go try ; work from the ages of twenty to sixty years daily and you will fail. The fact is, the time required to find the mathematically exact specific speed of a falling body in still air was almost that required to measure the distance of the nearest star, about 120 years.

Then Atwood invented his machine and this finally came to some near approach to accuracy. But this instrument of precision fell far short of the electrical-chronographic apparatus. When all of this very complex mechanism is in perfect order it releases the ball at the exact beginning of a second and records the absolute time on the cylinder of a chronograph electrically and repeats the process at the absolute end of the second so far as human hands are able to do rigidly accurate work. The moment that those supermen, Newton and Liebnitz, discovered that mighty power, beside which all else human pales into insignificance—the stupendous calculus of differentials—every mathematician saw immediately that one of Nature's most magnificent laws was found in falling bodies. And then began the relentless and arduous self-imposed work of more than a hundred years to find the set specific speed acquired by a falling body at the instantaneous and absolutely exact end of the first exactly measured second of time since man appeared. The result is one grand, all-potent all-powerful mean or average of a century of world-wide measures, the diamond of diamonds, the most valuable number in possession of man, the astronomical balance : 16.1 feet fallen to end of the first second ; 32.2 feet per second speed at end of first second That is, a body let fall will, under the action of the earth's attraction of gravitation, fall 16.1 feet during the first absolute second of time ; and at the absolute end of the second will be in motion with a velocity of 32.2 feot per second. These numbers constitute the most accurate and all-powerful scales in

existence. —"London Budget."