THE EARTH AS A PLANET 363 



All time-pieces are set to read noon throughout the time-belt when 

 only the places on a certain meridian running through the central 

 portion of this region really have the sun on meridian. 



While in theory these time-belts are seven and one-half degrees of 

 longitude in width on both sides of each of the time meridians, as a 

 matter of fact there are great departures from any such arrangement 

 to conform to the convenience of the traveling public. 



Sunrise during the Spring and Summer is so much earlier than the 

 hour fixed by custom for starting the wheels of the nation's industries 

 that in many ways it is advantageous to have the industrial day for 

 people generally begin at six o'clock rather than at seven A. M. 

 This makes the mid-day meal come at eleven instead of twelve 

 o'clock. Many difficulties, both civil and legal, would be involved in 

 any change in the hours established by custom and by statute for 

 beginning and closing the varied activities of life's affairs. Instead, 

 a "Daylight-Saving Plan" now followed in the United States and in 

 other countries decrees that at a certain date in the Spring all clocks 

 shall be set ahead one hour, and then set back one hour at a fixed 

 date in the Fall. 



The round of daily activities during the Spring and Fall then 

 actually begin one hour earlier every day and close one hour earlier 

 at night than during the other part of the year. But the times as 

 shown by the clock remain the same the year around. During the 

 Summer under this plan the sun is yet an hour's time from meridian 

 when the clock reads noon. People order their ways of life by clock 

 time rather than by sun time. 



