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Weights and Measures: Standard

Standard Time. -The introduction of standard time in 1883 was intended to lessen this confusion. It is based upon the selection of certain meridians, the mean solar local time of which differs by exactly one hour PACIFIC MOUNTAINT CENTRAL TIME EASTERN T TIME +120° +75° 1200 +105°+90° MEXICO +1059 U. +90° Map of Standard Time. 25 or multiples of one hour, and the agreement among railway authorities and others to adopt the local time of these meridians as a standard for intervening sections. The first of these meridians passes through Philadelphia, the second near New Orleans, St. Louis, and Davenport, the third near Denver, the fourth near Sacramento and Stockton. The moment that the sun crosses these meridians is taken for noon in all places not more than half an hour distant from it either east or west. Hence these meridians give rise to four belts governed by four different standards of time; namely, Eastern, Central, Mountain, and Pacific time, respectively. The lines dividing these are approximately halfway between the meridians of Philadelphia, St. Louis, Denver, and Sacramento, respectively.

In each of these belts railway time is uniform, and this is practically adopted by the entire population.

The traveler in passing from one belt to another merely changes his watch one hour to conform to the local time. The division into minutes remains unaltered.