LAND vSURVEYS 



87 



intervals and thus provide a systematic rather than hap- 

 hazard method of correction. In 1881 a regulation was 

 adopted which is still in force, providing for curvature cor- 

 rection by standard parallels and guide meridians run every 

 24 miles. The lines divide the area to be surveyed into 

 tracts 2 4 miles square. The correction for curvature is made 

 on the north side of the 24-mile tract at the standard parallel. 

 The rectangular system of land surveys may be con- 

 sidered as developing from 1785 to 1881. Previous to 1881 



(JT STANDARD PAR^L 



NORTH- 





* 

 * 



1 



rt 



5 1: 



&4IV R 3 W 



R.2 W R.n 



Initio! 

 point 



1ST STANDARD 



Fig. ioi. Showing the position of the initial point, base line, 



principal meridian, standard parallels, guide 



meridians, townships, and sections 



the method was altered every few years, the most radical 

 alterations taking place from 1785 to 1805. After this 

 time the changes made were for the purpose of eliminating 



