62 A MANUAL FOR NORTHERN WOODSMEN 
In elaboration of the law are the following rules laid 
down by the Federal Land Office: 
24. Existing law requires that in general the public lands of 
the United States “shall be divided by north and south lines run 
according to the true meridian, and by others crossing them at 
right angles so as to form townships six miles square, and that 
the corners of the townships thus surveyed “must be marked with 
progressive numbers from the beginning.” 
Also, that the townships shall be subdivided into thirty-six sec¬ 
tions, each of which shall contain 640 acres, as nearly as may be, 
by a system of two sets of parallel lines, one governed by true 
meridians and the other by parallels of latitude, the latter inter¬ 
secting the former at right angles, at intervals of a mile. 
25. In the execution of the public surveys under existing law, 
it is apparent that the requirements that the lines of survey shall 
conform to true meridians, and that the townships shall be six miles 
square, taken together, involve a mathematical impossibility due 
to the convergency of the meridians. 
Therefore, to conform the meridional township lines to the 
true meridians produces townships of a trapezoidal form which 
do not contain the precise area of 23,040 acres required by law, 
and which discrepancy increases with the increase in the con¬ 
vergency of the meridians as the surveys attain the higher latitudes. 
26. In view of these facts, and under the provisions of Sec¬ 
tion 2 of the Act of May 18, 1796, that sections of a mile square 
shall contain 640 acres, as nearly as may be, and also under those 
of Section 3 of the Act of May 10, 1800, that “ in all cases where the 
exterior lines of the townships, thus to be subdivided into sections 
and half-sections, shall exceed, or shall not extend six miles, the 
excess or deficiency shall be specially noted, and added to or de¬ 
ducted from the western or northern ranges of sections or half¬ 
sections in such township, according as the error may be in run¬ 
ning lines from east to west, or from south to north; the section? 
and half-sections bounded on the northern and western lines of 
such townships shall be sold as containing only the quantity ex¬ 
pressed in the returns and plats, respectively, and all others as 
containing the complete legal quantity,” the public lands of the 
United States shall be surveyed under the methods of the system 
of rectangular surveying, which harmonizes the incompatibilities 
of the requirements of law and practice, as follows: 
First. The establishment of a principal meridian conforming 
to the true meridian, and, at right angles to it, a base line conform¬ 
ing to a parallel of latitude. 
Second. The establishment of standard parallels conforming 
to parallels of latitude, initiated from the principal meridian al 
intervals of 24 miles and extended east and west of the same. 
Third. The establishment of guide meridians conforming tc 
true meridians, initiated upon the base line and successive standard 
