Standard Time. In the United States, when the sun is due south of a place it is noon at that place. Clocks set at 12 M. when the sun is due south show local sun time, which is the kind of time we have studied up to this point. It is readily seen that only clocks upon the same meridian will show the same sun time, or solar time. If a person were to go 1° west or east of any given meridian, his watch would be 4 minutes fast or slow.

To avoid this inconvenience, a system of standard time has been adopted. The United States has been divided into four standard time belts running north and south (see map). The most eastern belt is the Eastern standard time belt, and its standard time, i.e. the time for all places lying within this belt, is the correct solar time for the meridian of longitude of 75° W. The next is the Central time belt, and its standard time for the entire belt is correct sun time for the meridian of 90° W. Name each of the other belts. What meridian determines the standard time of each?

These boundary lines may be changed from time to time by Congress or by order of the Interstate Commerce Commission, to meet certain local conditions or to suit the convenience of the railroads.

In addition to these four meridians, the meridian of 150° W. has been established the time meridian of Alaska standard time.

By how many degrees of longitude are these standard time meridians separated? What is the difference in time between any standard time belt and the adjoining time belt?

How does the local sun time on the eastern margin of each belt compare with the standard time at that place? How does this difference vary as one moves westward toward the meridian from which the belt gets its standard time? How do local time and standard time compare at the meridian? Answer similar questions for the western half of the belt.

STANDARD TIME

1. When it is noon in the Eastern belt, what is the time in each of the other belts?

2. When it is noon by Mountain time, what is the time in each of the other belts?

3. In traveling from Philadelphia to San Francisco, would a traveler find his watch too slow or too fast, and by how many hours?

4. A traveler who left San Francisco at noon Sunday, Pacific

time, arrived in New York at noon Friday, Eastern time. How

long did it require to make the journey?

プ

5. What standard time do you use?

6. At what standard time does your school begin? What is the standard time then in San Francisco? in Salt Lake City? in New Orleans? in Philadelphia? in Kansas City? in Chicago? in Boston?

7. What is your longitude? What is the difference between your standard time and your local time?

between

8. If an intercollegiate football game was called at 2 P.M. standard time, at Palo Alto, California, what was the standard time in Columbus, Ohio? in New York? in Chicago? in Boston? where you live?

9. President Harding was inaugurated at 12:30 P.M. in Washington. What standard time was this in New Orleans? in Seattle? in Portland, Maine? in Minneapolis? in Denver?

N

B

Division of Land. In fixing the boundaries of farm lands as first laid out in the United States, that is, in the eastern states, little regard was paid to regularity of boundary; but in surveying the public lands of the United States, Congress adopted the simple and accurate method of dividing these lands by a series of parallel lines six miles apart running north and south and east and west. These parallel lines divide the land into townships, which are approximately six miles square. Range and Tier. A series of townships extending north and south is called a range; a series extending east and west is called a tier. Ranges are numbered east and west from a principal meridian; tiers are numbered north and south from the base line. A township is designated by the number of

W

A Range

Base

Meridian

Principal

S

FIG. 1.

A Tier

Line

the tier and the number of the range in which it is located.

Thus, township marked B, Fig. 1, is designated T. 3 N., R. 2 E., read township three north, range two east, which means that B is in the third tier north of the base line and in the second range east of the principal meridian.

Sections. A township is divided into sections approximately1 1 mile square and numbered as shown in Figure 2, beginning at the

A section is divided into quarter-sections, and the township, section, and quarter-section corners are permanently marked. Quarter-sections may be subdivided, if desired, into half-quartersections and quarter-quarter-sections.

DIVISION OF LAND

1. How many square miles are there in a township?

2. How many acres are there in a section? in a half-section? in a quarter-section? in a quarter-quarter-section?

In examples 3-8 make drawings similar to Figure 1, and locate with respect to the principal meridian and the base line:

3. T. 2 N., R. 3 W.

5. T. 4 N., R. 1 W.

7. T. 2 S., R. 2 W.

4. T. 2 N., R. 2 E.

6. T. 1 N., R. 3 E.

8. T. 3 S., R. 2 E.

9. Read N.W., Sec. 12, T. 3 N., R. 1 W.

10. Read S., Sec. 30, T. 2 N., R. 4 W.

II. Read W., Sec. 10, T. 2 S., R. 3 W.

1 Townships and sections would be exact squares if it were not for the fact that the meridians converge at the poles of the earth.

Make a drawing similar to Figure 3, and locate each of the following tracts of land; give the number of acres in the tract:

12. S. of N.W. .

13. W. of S.E. 1.

14. S.E. of N.E. .

15. S.W. of N.W. 1.

16. How many rods of fence are required to enclose S.E. of Sec. 12 (see Figure 3)?

17. How many rods of fence are required to enclose N.E. of S.W. of Sec. 12 (see Figure 3)?

Volumes. The number of cubic units that a solid contains is called its volume.

As you have already learned how to find the volumes of rectangular solids, it is necessary now only to review and to apply what you have learned.

1. The volume of a cube is equal to the cube of its length. NOTE. See note, page 121.

Thus, if the cube represented by Figure 1 is 4 ft. long, 43, or 64 = the number of cubic feet in the cube, or its volume.

2. The volume of a rectangular solid is equal to the product of its three dimensions.

Thus, if the rectangular solid represented by Figure 2 is 4 ft. long, 3 ft. wide, and 5 ft. high,

5X3X4, or 60=the number of cubic feet in the rectangular solid, or its volume.