A treatise on land-surveying; comprising the theory developed from five elementary principles; and the practice with the chain alone, the compass, the transit, the theodolite, the plane table, &cIllustrated by four hundred engravings, and a magnetic chart . NED. 125) All the methods which have been explained in the threepreceding chapters — Surveying by Diagonals, by Tier-lines, andby Perpendiculars, particularly in the form of offsets—are fre-quently required in the same survey. The method by Diagonalsshould be the leading one; in some parts of the survey, obstaclesto the measurement of diago
A treatise on land-surveying; comprising the theory developed from five elementary principles; and the practice with the chain alone, the compass, the transit, the theodolite, the plane table, &cIllustrated by four hundred engravings, and a magnetic chart . NED. 125) All the methods which have been explained in the threepreceding chapters — Surveying by Diagonals, by Tier-lines, andby Perpendiculars, particularly in the form of offsets—are fre-quently required in the same survey. The method by Diagonalsshould be the leading one; in some parts of the survey, obstaclesto the measurement of diagonals may require the use of Tie-lines ;and if the fences are crooked, straight hues are to be measurednear them, and their crooks determined by Offsets. (126) Offsets are necessary additions to almost every othermethod of surveying. In the smallest field, surveyed by diagonals,unless all the fences are perfectly straight lines, their bends mustbe determined by offsets. The plat (scale of 1 chain to 1 inch),and field-notes, of such a case are given below. A sufficient num- CHAP. IV.] Diagonals, Tic-lines and Offsets. S3 ber of the sides, diagonals, and proof-lines, to prove the work, shouldbe platted before platting the offsets. Fig. 3. 0 0 360 6 315 10 275 UJ n 5 215 eS 0 150 0 115 10 80 5 65 8 B or B 0 125 UJ 11 90 Q 00 23 62 12 22 0 A L. O U O 2 a _i
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectsurveying, bookyear18
