UNIT OF ELECTRICITY

Evening Star, Issue 19840, 13 April 1928, Page 9

UNIT OF ELECTRICITY

WHAT IT WILL GO TWENTY UTILITY SERVICES The term “ Electricity ” is derived from the Greek word “electron,” moaning amber, so called because of its power of attraction. Electricity has the power of attraction, not only in the sense of magnetic influence, but also in the sense that it is the “elect” power, chosen on account of its great cleanliness, convenience, and adaptability in all its uses. It follows, therefore, that nearly everyone nowadays wants to know something about electricity. It may be that they are only prompted by curiosity to know ” how it works,” or, perhaps, they have a natural bent for things scientific, and are attracted in the first instance by the many wonderful manifestations of the powers of the electric current which are so evident in our ordinary daily life. Many people have grown so accustomed to electric light, electric trams, telephones, and even the more recent “wireless,” that they have ceased to regard them with the admiration which is really deserved, but natural inquisitiveness prompts the questions “How?” and “Why?” What is “ Electricity ’’—that wonderful, invisible force which lights our homes, propels our trams, drives our factories, sends messages over thousands of miles in a few seconds, and renders many other services' of the greatest value to mankind? Mho can say? Not one of the most learned scientific men the world lias yet seen has been able to explain what electricity really is. We cannot see it; it lias no color, odor, form, or weight, yet it can he produced at will, and its effects can be controlled with the greatest ease and certainty. The simplest way to regard it is as a form of energy produced by the application of sonic other form of energy, it is a wellknown scientific law that energy cannot be created—it can only be converted from an existing form into another form. Thus, in a machine which is used for “generating” electricity, it is tUe mechanical energy used to drive the machine which is converted into the electrical energy given out in the form of voltage and current. Therefor© wo do not make electricity in the sense of producing it from nothing; we merely obtain it by converting some already existing supply of energy into electrical energy. Tho electricity so generated at the power station is now distributed through cables or supply mains laid in the streets over wide areas to the houses possessing appliances which are to ho operated for our benefit—viz., for lighting, power, heating and cooking, chemical processes, etc. As electricity is sold at so much per unit, the consumer naturally wants to ly 1 ' 0 '" something about the Unit or Electricity. This may he easily understood from its analogy with the How of water in a pipe. . , The rate of flow of water, is measured in gallons per minute or hour; the pressure or force by the “ head ■ of the number of feet through "Inch the water falls; and the power obtained is a product of the flow and the pressure. Similarly with electricity, the rate ol flow is measured in “ amperes ■, the pressure is measured in ‘ volts, ami the power obtained is the product ot the flow (amperes), and the pressure (volte), the result being “watts. For convenience 1 ,U< h> watts is taken as the commercial unit of power, and is termed “kilowatt.” Due knoiiatt npplied for one hour is piie kilowatthour or one unit ol electricity. One electrical horse-power _is (4b watts, therefore one kilowatt is equal to 1 1-3 electrical horse-power. One fiftv-ciinclle-power lam]) will require sixty watts, and therefore one kilowatt is equal to (approximately) 17-50 candle-power lamps; hence H-oO candle-power lamps alight lor one hour will consume one unit of electricity. One unit of electricity can only he consumed when one kilowatt (1,000 watts) is actually in use for one hour, therefore it the use of the one kilowatt be intermittent the periods ol use must total one hour bclore one unit is consumed. Also, where the use is variable, such as for motor power, the actual time taken to consume one unit will exceed the apparent time to pin extent depending upon the variations in US Thc following examples will show what one unit of electricity will do:— 1. Run a vacuum cleaner for five hours. , , 2. Iron (smoothing) light fabric tor three hours. 3. Drive a sewing machine (or eight hours. 4. Operate a. washing machine lor four hours. 5. Heat a moderate-sized room lor one hour, or a larger sized room for half an hour.

6. Keep the breakfast warm for ten minutes each morning lor two months. 7. Toast the bread each morning for one week.

8. Make twenty cups of coffee. 9. Grill twelve chops or steaks. 10. Boil seven kettles, each holding one quart of water. 11. Provide five gallons of hot water per day. 12. Mince 1001 b heel.

13. Do the cooking for the family on an electrics cooker, consumption averaging about one unit per person per clay. 14. Heat tho shaving water each morning for two months, 15. Heat the curling tongs each clay for three months. 16. Warm the bed for one hour each night for one month.

17. Polish 2,001) knives. 18. Bun a plate polishing machine for eight hours. If). Run a portable ventilating fan for twenty hours.

20. Provide eight hours’ use of an electric soldering iron.