3. When it is 6 o'clock A.M. standard time in Chicago, find by using Fig. 217 the time in New York, St. Louis, Denver, San Francisco.

4. Try to find out what other countries have adopted the use of time belts, and what longitude determines the time in such countries.

113. Daylight saving. Standard time was introduced because it removed the inconvenience caused by the continuous change of local time to persons traveling east or west. Changes in time may be desirable for other reasons. During the World War, when coal became scarce because of the large amounts used in factories supplying the government with war materials, an arbitrary change in time was made to help preserve the coal supply. The clocks were moved one hour ahead. With this change a person who ordinarily retires at 9 P.M. really retires at 8 P.M., and gains an additional hour of daylight without losing an hour in the morning. The result is a saving of light and coal.

Some people liked this plan very much. It made the electric-light bills a little less for the family, and considerably less for factories and large stores. It lengthened the day during the summer months, giving the working people an extra hour of recreation in daylight and enabling those who had gardens to spend time on them after school or working hours.

Some people objected to the plan, especially the farmers. They were always early risers, but with daylight saving they had to rise even earlier in order to complete the necessary amount of work and to get their products to the trains at the right time. The extra hour of daylight proved to be a hardship to them.

People who traveled were greatly inconvenienced because the railroads did not adopt daylight saving, which made railroad time differ from daylight-saving time used in various cities.

Another objection to the daylight saving plan comes from mothers and doctors, who say that small children cannot get the proper amount of sleep, because under the new plan the children must be put to bed before dark.

However, in spite of these objections some cities continued the daylight-saving plan even after the war.

EXERCISES

1. Some tourists left the hotel at 8:30 A.M. to take a train. When they reached the station 10 minutes later, the clock in the waiting room gave the time as 7:40 A.M. How do you explain this if both clocks gave the correct time?

2. We left Chicago at 10:00 A.M., daylight-saving time. Having traveled at a moderate speed we stopped in a city in Indiana 49 miles from Chicago to have lunch. According to the clock in the restaurant it was only 10:45 A.M. How fast did we travel?

USES OF THE CIRCLE IN MEASURING PUBLIC
UTILITIES

114. The need of accurate measurement. During the World War when it was difficult to secure help, gas companies of the larger cities had to employ many incompetent workers for their meter service. This resulted in thousands of complaints from citizens who claimed that their gas bills were too high for the amount of gas used. Errors in gas bills were due, mainly, to carelessness or ignorance in reading meters and in

recording the readings, and to inaccurate calculation of the bills by the bookkeepers. At all times users of public utilities should be able to check the correctness

of their gas and electric-light bills. They should know how to read a meter and be able to calculate the correct amount to be paid to the company.

115. How gas is measured. In many cities gas used for cooking and illuminating is made from coal.

It is kept in large tanks from which it is forced into pipes leading to the houses of the consumers.

CUBIC

FEET

UNITED

GAS

COMPANY

MFG

The cost of gas is usually fixed at a certain sum per 1000 cubic feet. The number of cubic feet used is recorded by the gas meter. The amount is shown by means of circles (dials) divided into 10 equal arcs (Fig. 218). Each division on the righthand circle denotes 100 cu. ft.; on the center circle 1000 cu. ft.; on the left-hand circle 10,000 cubic feet.

As gas is being used the hands turn in the direction 0, 1, 2, etc.

The middle dial is numbered in a direction reverse to that of the other two.

When reading a meter, always note the figure just passed by the hand. The meter is read from the lefthand dial to the right. In Fig. 218 the first hand has passed over 6, the second over 5, and the third over 7. Accordingly, the reading is 65,700, which means that 65,700 cu. ft. of gas have been used.