LAND SURVEYS 89 



then adopted, and now the principal meridians may be con- 

 sidered as having special names, including the six that were 

 numbered. They are designated as First, Second, Black 

 Hills, and Boise, for example, the name of the meridian 

 implying the corresponding initial point and base line. 

 Twenty-seven principal meridians have been established in 

 the United States. 



Standard parallel. Beginning at the initial point, on the 

 principal meridian, lines are run east or west every 24 

 miles parallel to the base line and of such length as the 

 area to be surveyed may call for. These lines are known 

 as standard parallels and are numbered consecutively north 

 or south, from the base line. 



Guide meridians. On the base line and on each standard 

 parallel every 24 miles, beginning at the principal meridian, 

 lines are run due north as far as the next standard paral- 

 lel. These lines are known as guide meridians and are 

 numbered consecutively east and west, beginning next to 

 the principal meridian. 



Township exteriors. On the completion of the standard 

 parallels and the guide meridians, the boundaries of the 

 townships are surveyed, the surveyors beginning at the 

 southwest corner of the 24-mile area and resurveying the 

 first 6 miles of the standard parallel, then running due 

 north 6 miles, then running west on a random line to the 

 corner which, was set on the principal meridian 6 miles from 

 the initial point. Since some errors will be involved, the 

 distance is measured between the actual corner and the 

 point of intersection of the random line and the principal 

 meridian. The true line is then run from the principal 

 meridian back to the northeast corner of the township. 

 The line north is continued from the northeast corner 6 

 miles and again run west to the principal meridian. In 

 this way the townships are extended north. The inter- 

 section of the east side of the north township with the stand- 

 ard parallel is marked "closing corner." Owing to the 



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