Home › Weights and Measures › Weights and Measures: Coast

Weights and Measures: Coast

In practice the lines adopted for the demarcation of the time belts are not true meridians but conform to the location of centers of population and other local conditions. The first section, Eastern time, includes all the territory between the Atlantic Coast and a broken line drawn from Detroit to Charleston, S. C.; which is the most southern point. The second section, Central time, includes the territory between this eastern line and a broken line running from Bismarck, N. D., to the mouth of the Rio Grande. The third section, Mountain time, includes the territory between this central line and a line representing nearly the western borders of Idaho, Utah, and Arizona. The fourth section, Pacific time, runs thence to the Pacific Coast. Standard time is uniform inside each of these sections and the time of each section differs from that next to it by exactly one hour. Thus, at 12 noon in New York City, Eastern time, at Chicago, Central time, it is 11 A.M.; at Denver, Mountain time, 10 A.M.; at San Francisco, Pacific time, 9 A.M. Standard time at Boston is 16 minutes earlier than mean solar local time; at New York, 4 minutes earlier; at Washington, 8 minutes faster; at Charleston, 19 minutes faster; at Detroit, 28 minutes slower; at Kansas City, 18 minutes faster; at Chicago, 10 minutes slower; at St. Louis, 1 minute faster; at Salt Lake City, 28 minutes faster; at San Francisco, 10 minutes faster.

This difference between standard and mean solar local time causes some inconvenience. At some points, sunrise, noon, or sunset may vary from standard time as much as half. an hour. The variation, however, cannot be greater than this, and in some localities is very slight. This difference may affect such matters as the hour for meals and the time given in the almanac (which is based on mean solar local time) as the hour of sunrise or sunset. Proper adjustments can be made, however, by estimating the difference in time between the meridian of the place and the standard meridian at the rate of four minutes to each degree of longitude. Standard time is now in use practically throughout the civilized world. The difference in time between two places can be easily determined by observing on a map their distance apart in degrees of longitude and allowing four minutes to each degree based on the following calculation: 1440 minutes... revolution of the earth. 1 revolution of the earth is 360 degrees.

Therefore, 1 degree....... lay, or ..4 minutes.

The following is a table of the standard for the measurement of time: 60 seconds. 60 minutes.......... 24 hours... 7 days........ 4 weeks...... 28 days.... 30 days (in computing interest)... 28, 29, 30, or 31 days. 12 calendar months.. 13 lun. mo., 1 day, 6 hours... 365 days... 366 days 3651 days. cid 52 weeks and 1 day (12 cal. mo.) 1 minute. 1 hour. 1 day. 1 week. 1 lunar month. 1 lunar math. 1 month. 1 cal. month. 1 year. 1 Julian year. 1 com. year. 1 leap year. 1 Julian year. 1 year. 865 d., 5 h., 48 m., 49 s.......1 solar year. 365 d., 6 h., 9 m., 12 1 sidereal year. 100 solar years... .1 century.

The Calendar.-The following jingle will be found convenient to recall the variations in the calendar months:

Thirty days hath September, April, June, and November; All the rest have thirty-one Except the second month alone Which has but twenty-eight, in fire, Til leap year gives it twenty-nine.

The common year has 365 days, or 52 weeks and 1 day; the leap year 366 days.