The earth revolves on its axis from west to east, nearly 17.3 miles in 1 minute at the equator; at the latitude of New Orleans, nearly 15 miles in 1 minute; at Memphis, 14 miles; at Chicago, 13 miles; at London, 10.8 miles; at St. Petersburg, 8.6 miles. That is, a watch would gain one minute going west, or lose one minute going east that distance, in the latitudes of the respective cities.
The globe is divided into zones of 15 degrees or one hour breadth, the Greenwich meridian being in the center of the zero zone. Thus Belgium and Holland (since 1892) keep Greenwich time; Denmark, Sweden, Switzerland (1894), Austrian railroads, Germany, and Italy (1893) keep the time of longitude 15 degrees East—i.e. one hour earlier than Greenwich. In North America again five zones are distinguished. The corresponding times are distinguished as Eastern (671⁄2 to 821⁄2 degrees), Central (821⁄2 to 971⁄2 degrees), Mountain (971⁄2 to 1121⁄2 degrees), and Pacific (1121⁄2 to 1271⁄2 degrees) times.
New York people are in the Eastern Time Belt. If they rise at six o’clock in the morning, [866] they will be up a whole hour before Chicago people, who get up at the same hour.
The clock at Greenwich, near London, England, from which the standard time of the world is reckoned.
Thus, each day begins an hour sooner in New York than in Chicago, two hours before Denver, and three hours before San Francisco.
Standard time in Japan is nine hours earlier than Greenwich time.
In the western parts of Canada the twenty-four hour system has been adopted, under which four P. M. becomes sixteen o’clock and so on. Steps are being taken to introduce it generally in India, Belgium, and the United States. It is of special convenience in the construction of railroad time tables; and it has long been used by the Italians and by astronomers.
SIMULTANEOUS TIME IN LONDON, NEW YORK, AND BOMBAY