I08 BROWN : 



time of Greenwich Observatory is in use ; in France, that of 

 Paris ; in Italy that of Rome ; and so on. 



But the United States is very wide, so wide that no one 

 standard will suffice. The country, therefore, is divided into 

 four zones of fifteen degrees of longitude each, corresponding 

 to one hour of time. 



The EASTERN ZONE, 7° 30' on each side of the meri- 

 dian 75° W. of Greenwich, which meridian passes very near 

 Philadelphia. 



The CENTRAL ZONE, 7° 30' on each side of the meri- 

 dian 90° west of Greenwich. Which meridian passes very 

 near New Orleans and St. Eouis. 



The MOUNTAIN ZONE, 7° 30' on each side of the 

 Meridian 105° W. of Greenwich, which meridian passes very 

 near Santa Fe, New Mexico, and Pike's Peak, Colorado. 



The PACIFIC ZONE, 7° 30' on each side of the meridian 

 120° west of Greenwich, which meridian passes not far to the 

 east of Sacramento, Cal. And, roughly speaking, follows the 

 course of the Rocky Mountains. 



There is also a Colonial Zone to the east of the EAST- 

 ERN ZONF:. It is wholly outside of the United States, and 

 it is not often mentioned. 



Those cities which are near the middle of the Zone are the 

 most fortunate ; for their local mean solar time differs but 

 little from standard time, and the time of the contiguous 

 Zones does not concern them. Philadelphia, for example, 

 and, exactly speaking. The City Hall, is by the U. S. Coast 

 and Geodetic Survey in Ion. 75° 9' 50.53" west of Greenwich 

 and its local time differs only forty seconds (nearly) from 

 Eastern Standard time. Those cities, on the contrary, which 

 are at the boundaries, have to keep three different records. 



It will thus be seen at once that those Standard time pieces 

 (so to speak for brevity's sake) those standard time pieces 

 only which come into iise on the meridians which bisect each 

 zone of time will agree with the sun on Zero Day. For at all 

 other ])()ints mean noon and standard noon, lit-ing parts of 



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