But in cases where lands are overflowed by artificial means, such as dams for milling, logging, etc., such overflow will not be officially regarded, but the lines of the public surveys will be continued across the same, without setting meander posts, stating particularly in the notes the depth of the water and how the overflow was caused.

ORDER OF CARRYING FORWARD THE PUBLIC

SURVEYS.

In the preceding pages we have explained-1st, the system of dividing the public lands into rectangular tracts of convenient size to be disposed of for pastoral and agricultural purposes; 2d, the manner of coursing, measuring, and marking the lines of the public surveys; 3d, the · mode of establishing and perpetuating the corner boundaries of the public lands; and 4th, how the field book, which is the permanent record of everything officially done or observed by the deputy surveyor and his assistants, is to be kept, with full instructions as to the objects and data required to be recorded therein.

We are now prepared to explain the order in which the public surveys are carried forward in the field. First, then, let us suppose for illustration, that it is required to commence operations in a new territory where no public surveys have been made.

Meridians and Base Lines.-It will be remembered that all government surveys are projected from previously established meridians and base lines, or standard parallels. Before proceeding to lay off townships, therefore, a meridian and base line must be surveyed and marked, unless the proposed surveys are in continuation of those already executed in an adjoining state or territory, from an existing base.

Meridians may be run either north or south as may be necessary to reach the locality desired. They must, however, be run on a due north or due south course, the half

mile, the mile, and the six mile corners being accurately measured and durably perpetuated according to the instructions in the preceding pages. Base lines may be

run on either a due east or due west course from the meridian, planting the half mile, mile, and township corners at the prescribed intervals, FULL MEASURE.

Initial Point. The first step in proceeding to establish a meridian and a base line, will be to select some prominent natural land-mark convenient to the locality where the earliest surveys will be needed, for an initial or starting-point. An isolated, well-defined mountain, or the point of confluence of two rivers, afford favorable objects for the purpose indicated. If these are not to be found, some other permanent natural object should be sought for.

Standard Parallels or Correction Lines.-It may also be necessary to run one or more standard lines in the early part of the surveying operations, for it will be borne in mind that all range lines are to be run north from base or standard lines. Standard parallels, like base lines, may be run on either a due east or due west course from the meridian, planting the half mile, mile, and township corners at the prescribed intervals, full measure.

These lines form the skeleton or framework upon which to hang or build up the public surveys. Having provided the proper basis for this operation as directed, the deputy surveyor will next proceed to survey

Principal Meridians.-As the public surveys progressed westward, six meridianal lines, denominated Principal Meridians, have been established and designated in numerical order from east to west, to wit:

The 1st Principal Meridian runs north from the mouth of the Great Miami river, between the States of Ohio and Indiana to the south boundary of Michigan.

The 2d Principal Meridian runs north from the mouth of the Little Blue river, through the center of the State of Indiana to its northern boundary.

1. EXTERIOR OR TOWNSHIP LINES.

Systematic order is observed in running township lines, and the perambulations of the deputy surveyor are fully illustrated by Diagram A, on page 54.

TOWNSHIPS WEST OF THE MERIDIAN.-Begin at the first pre-established township corner on the base line, west of the meridian, which will be the southwest corner of Township 1 N., Range 1 W., marked No. 1 on the diagram: thence north on a true meridian line 480 chains, establishing the section and quarter section corners thereon as per instructions, to No. 2, where establish the corner to Townships 1 and 2 N., Ranges 1 and 2 W.; thence east on a random line, setting temporary section and quarter section stakes to No. 3, where measure and note the distance at which the eastern boundary is intersected north or south of the true or established corner. Then, calculating a

The 3d Principal Meridian runs north from the mouth of the Ohio river through the center of the State of Illinois, terminating at its northern boundary.

The 4th Principal Meridian runs north from the Illinois river through the western part of Illinois and the center of Wisconsin to Lake Superior.

The 5th Principal Meridian runs north from the confluence of the Arkansas and Mississippi rivers through the eastern portion of the States of Arkansas, Missouri, and Iowa, and governs the surveys in Minnesota lying west of the Mississippi river, and also in Dakota lying east of the Missouri river.

The 6th Principal Meridian commences on the Arkansas river, in the State of Kansas, and runs north through the eastern part of Kansas and Nebraska, terminating at the Missouri river.

Independent Meridians. In addition to the six principal meridians above described, a number of Independent Meridians have been established in the newer states.

In New Mexico the surveys are reckoned from the Independent Meridian of New Mexico. In Utah, the Independent Meridian is styled the "Salt Lake Meridian." The surveys in Oregon and Washington Territory are governed by an Independent Meridian called the "Willamette Meridian," and in California there are three Independent Meridians governing the different surveys in that state, named respectively "Humboldt Meridian," " Mt. Diablo Meridian," and "St. Bernardino Meridian." The surveys in Nevada are numbered from the "Mt. Diablo Meridian" in California.

course that will run a true line back to the corner from which the random started, run and measure westward, to No. 4, which is identical with No. 2, establishing the permanent corners on said line and obliterating the temporary corners on the random, throwing the excess or deficiency in measurement on the west end of the line.

If in running the above random line the deputy should fall short or overrun in length, or intersect the township boundary at more than 3 chains and 50 links north or south of the true corner, either of which would indicate a material error in the work, the lines must be retraced, even if found necessary to remeasure the meridianal boundaries of the township.

Proceed in the same manner from No. 4 to No. 5-from No. 5 to No. 6-from No. 6 to No. 7-and so on to No. 10. From No. 10 run north, still on a true meridian, establishing the mile and half mile corners until the standard parallel is reached at No. 11, throwing the excess over or deficiency under 480 chains upon the last half mile, according to law; and at the intersection establish the township "closing corner," measuring and noting the distance to the nearest "standard corner" on said parallel.

Should it happen from any cause that the extension of the correction parallel above the field of operations has been delayed, the deputy will plant the corner of the township in place, subject to correction when the parallel shall be extended.

The deputy will then return to the S. W. corner of Township 1 N, Range 2 W. on the base line, at No. 12, and proceed in a similar manner to No. 33, returning and running each range line north from the base line.

It is sometimes desired to reach a locality not intersected by the meridian or base line. The manner of accomplishing this is illustrated by Diagram A. For example, the meridian may be extended south to such