ELECTRICAL TERMS.

Waipa Post, Volume XXI, Issue 1280, 12 August 1922, Page 3

ELECTRICAL TERMS.

WHAT IS A WATT t

HOW ELECTRICITY IS MEASURED,

The language of the electrician is Greek to most • people,. Whilst he talks glibly of volts and amperes and watts, they know only that they have to pay an electric light bill for so many units, and let it go at that! Though electricity is not a fluid, we can understand most of its terms by Comparing it with water flowing through a pipe. If we turn a stream of water on to the paddle of a water wheel, the work that the wheel will do depends upon two thirgs-—the amount of water delivered every 'second and the pressure of the stream. We measure the first in gallons and the .second in pounds. Finding the Cost.

In the case of electricity, we measure the rate at which it flow:s in iampheres, and its pressure in voltsi The work which it will do is found by multiplying amoeres and volts together, which gives the answer in watts, or units of energy. The Board of Trade unit is l 1000

watts, often called a kilowatt which is the electrical equivalent to one horse-power. You will find the number of watts they require engraved on most electric lamps, and from this you can discover what they will cost to use. A 24-watt lamp will use one unit of 1000 wattsl in forty hours’ burning ; and if electricity costs tenpence a unit, the lamp will work out at a farthing an hour.

The ohm is another electrical measurement which can be understood by a comparison with water. Water flows easily through a large pipe, but if the pipe is narrow only a sma’l quantity can force its way through What the pipe isi to water, the wire is to electricity. The smJallor the wire, the more' difficult electricity will find it to pass, because the fine wire resists the flow. The electrician measures wires by their resistance in ohms.

One Westport paper announced a “ scoop ” recently iby declaring that wreckage from the lost steamer Kairaki 'had been found off Birchfield. Its local contemporary wa>ed humoro is aJbout the alleged sensation, and inserted the following paragraph: “The mystery solved.—Captain Sawyer, coming fiom Karamea bv the s.s. Nile yesterday steamed clo5« up to the object of curiosßy in the s*-a opposite Birchfield in cnticiparion of striking a treasure ship with fabulous wealth stored in its hold, but found to hid utter disappointment tha f the mystery was nothing more or loss than a tree above the water.” Tlie t reply of the other journal was to this effect : “ The idea that it is a snag, not 'a wreck, is absurd, as snags that we have seen have no doors with brass hinges or Baltic timber attached to them. A gentleman who called at this! office yesterday stated that the vessel can be plainly seen from the train, and we advise those persons who have snags on the brain to go to the scene and view the wreck.”