MEASURING THE INVISIBLE.

Manawatu Herald, Volume XLV, Issue 2600, 30 June 1923, Page 4

MEASURING THE INVISIBLE.

ELECTRICITY, THE POWER INVISIBLE. WITHOUT TASTE, SOUND OR ODOUR IS MEASURED EXACTLY ' “Ten pounds of electricity please.” A grizzled farmer from the agricultural precincts stepped up to the professor of science in an agricultural college and thus addressed him. “I hev read a good deal about, this here ‘lectricity’ ” the good man from the far country ventured, “bout how it will light homes, and churn and milk and I want to know just about how much of this here ‘lectricity’ you calculate I ougbter buy in order to light my home, and run my separator and give Mandy a helpin’ hand at times.” The college professor explained as best he could that electricity was not a visible commodity; that it could not be sold by the quart or pound, but was a force which man has found in the atmosphere and from which it is obtained by machines called generators or dynamos. As long as these machines or generators operate, electricity is kept in constant supply and' may be led with convenience and ease from one task to another by a system of conductors called wires. Electricity requires neither space nor place. So far as we know it takes up no room. Therefore wires are solid, like a bar of solid iron, only made of copper. Now as soon as the generator or dynamo stops, instantly the electricity ceases to flow from it, and the wires are just as inert and dead as any piece of metal. No old farmer may come to you and ask to buy electricity bv the pound like a bushel of potatoes or a pound of sugar. Such things happened years ago when the scientist himself was in comparative ignorance of much that we know now about the.new force that was destined to become the universal servant of mankind. Yet it is a significant fact that few of us to-day realise that if the agriculturist had asked for ten amperes of electricity it could have been measured out to him with just as much accuracy as if it were drugs or groceries. And mark this difference, that the ampere-meter measures electricity which occupies no space, moves from place to place in infinitely short intervals of time, is an invisible force, and, which no human being can satisfactorily explain.

SOME THEORIES ON WHAT ELECTRICITY IS. Scientists have given us some interesting theories about electricity. Some maintain that the reason it takes up no space is because it is believed to travel on the surface of the wire in the form -of a strained condition of the infinitely small particles of \fyhich every solid object is believed to be composed. These particles are too small to see under any microscope that has ever been invented, but scientists can figure out themarvels of chemistry and electricity in no other way, and so in order to satisfy human reasoning we call them atoms, and say they are the smallest divisions of all substances. But to get back to our friend of the soil, how is he to be supplied with his electricity? That is simple enough. He will buy his amperes and his volts through a small farm lighting outfit such as engineers have designed and placed on a successful, practical operating basis, a machine which uses gasolene instead of steam or water. And with his outfit he will probably use some very interesting and delicate little instruments called meters. Now these are among the most wonderful of all the works the electrical engineer has ever invented, h or it is with these meters that the amperage, or amount, of electricity and the voltage or pressure are determined to a remarkably accurate degree. The chemist scales that will weigh the mark of a lead pencil has no finer workmanship in its agate bearings than the electrical measuring instruments which are turned cut by the thousands in the electrical instrument laboratories. Every power plant, no matter whether it is built for the regular lew voltage farm light and power system or the largest power-house, must have its equipment of electrical measuring instruments. They are necessary to regulate the generators so that there will be a steady and uniform output of power. With both amperage and voltage kept at a steady flow there will be no flicker on the lighting circuit, no danger of blown fuses or of burned out lamps and lines will not be overloaded. “AUTOMOBILE METERS.” To-day one of the marked developments in measuring the invisible force of electricity is the develop-, ment of electric starting and lighting systems for automobiles. Nearly every automobile provided with electric equipment has a small ampere metei' on the instrument board. This instrument shows the amount of current generated and used for the purpose of keeping the storage battery charged. The amperemeter must have its indicating mechanism mounted in bearings as delicate as a watch. It is subjected to variations of heat and cold and weather, and to the jars and jolts of road service, yet these conditions must be met in an instrument which is made also at such low cost that it is among the most inexpensive of automobile accessories and yet surprisingly accurate and trustworthy. A , new type of such a meter has just been 1 brought out. In the new invention the'instrument operates without even -an electrical connee-

tion, the indicator registering from llie induction of a connecting wire threaded through a metal eyelet, and thus making the new appliance very simple and easily installed.