The electric meter may be checked approximately by the householder without the use of electrical instruments. For this purpose it is only necessary to note the reading of the meter, then turn on a number of lamps and note the time in hours required to cause the index of the dial farthest to the right to advance one division. It is necessary to use lamps which are rated in watts, as is done with most incandescent lamps now made. If the meter is modern, it will have a dial marked "kilowatt hours," and one division on the dial farthest to the right is a kilowatt hour, which means 1000 watt hours. For example, if 10 lamps, each marked 25 watts, are lighted at a given time, the rate of using electrical energy is 10x25 = 250 watts. In 4 hours these lamps will use 4x250 = 1000 watt hours, and this should cause the index of the dial farthest to the right to advance one division. As it is not possible to read a single division accurately, the lamps may be allowed to run until the index has moved over several divisions. If more lamps can be turned on, or larger lamps used, the time required for the test will be reduced.

The preceding test is approximate but will settle the question of whether any large error exists in the meter. To make an accurate test requires portable watt hour meters or other electrical apparatus which is suitable for use only by meter inspectors.

It is desirable for the householder to read the meter at the time it is read by the meter man, and to keep a record of the readings and the dates, in order to have the means of checking the bill rendered by the company.

When the bill for electric current seems unduly high, the meter is often first suspected; in reality it is usually the last thing to blame. Some of the reasons for higher bills are as follows:

1. Cloudy or rainy weather, requiring use of light in daylight hours.

2. Additional lamps may have been installed, or small lamps may have been replaced by larger ones.

3. Old dim lamps may be in use; in order to secure sufficient illumination more of them must be lighted than would be necessary if lamps in good condition were used. A dim lamp takes practically as much current as a new one, and is very wasteful to use. With lamps in good condition, the light will not be efficiently produced if the electric company allows the voltage to be low. In this connection it may be well to state that the tungsten lamp has been improved in quality and reduced in price to such an extent that no customer can afford to use carbon lamps. Many householders cling to the use of carbon lamps because they are usually supplied free. The folly of this course may be realized from the following statement: The cost of a lamp is reckoned in cents, but the cost of the energy to operate it during its life is a matter of dollars. The energy cost for a tungsten lamp is only about one-third that of the carbon lamp.

4. Lamps are sometimes left burning for days in attics, closets, and other out-of-the-way places.

5. Electric laundry irons, toasters, or other heating devices may have been placed in service or used more than in former months. Motor-driven devices may have been installed. Many devices which are operated through flexible cord from a lamp socket take very much more power than any lamp which would be used in the household. If is often erroneously believed that because such devices can be operated from a socket they require no more power than a lamp. The extent of this error may be realized from the statement that a six-pound laundry iron takes as much power as twenty tungsten lamps of about 20 candle-power each.

6. Defective wiring may allow current to flow when no lights or other devices are in use.

7. When electric elevators or electrically driven machinery is used and not properly oiled and cared for, excessive friction may result, with a corresponding waste of power and increase in the bill for electric current.

8. An error may be made by the company's meter reader, so that the bill rendered is too high or too low. If it is too high, the bill for the following month will be low by the same amount, if the meter is then read correctly, so that the consumer will not usually lose anything in the end. When a minimum monthly charge is made by the company, the consumer may lose. Hence, if an error has apparently been made by the meter reader, the company should be requested to investigate the matter and to render a corrected bill if an error is found.