By this is meant time which differs from Greenwich mean time by whole
hours.
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 (67-1/2 to 82-1/2
degrees), Central (82-1/2 to 97-1/2 degrees), Mountain (97-1/2 to
112-1/2 degrees), and Pacific (112-1/2 to 127-1/2 degrees) times.
New York people are in the Eastern Time Belt. If they rise at six
o’clock in the morning, they will be up a whole hour before Chicago
people, who get up at the same hour.
[Illustration: 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.
[Illustration: SIMULTANEOUS TIME IN LONDON, NEW YORK, AND BOMBAY
This diagram illustrates the curious fact that a telegram despatched
from London may be delivered in New York apparently before the time it
was sent off, and why a telegram apparently takes so long to reach
Bombay.]
[Illustration: COMPARATIVE TIME ALL OVER THE WORLD WHEN NOON AT
GREENWICH]