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 . Field-Booh No. 2 (Fig, 75) shews the ColumS method, exolai*ed in Art. (95). 86 CHAIN No. 3. [PAM! II. Meld Booh No. 3 (Fig. ^Q} is a convenient combination of ih#two preceding methods. The bottom of the Boot is at the side oftiiis figure, at A. CHAP. IV.] Diagonals, Tie-lines and Oflsets. 87 (128) It will easily appear
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 . Field-Booh No. 2 (Fig, 75) shews the ColumS method, exolai*ed in Art. (95). 86 CHAIN No. 3. [PAM! II. Meld Booh No. 3 (Fig. ^Q} is a convenient combination of ih#two preceding methods. The bottom of the Boot is at the side oftiiis figure, at A. CHAP. IV.] Diagonals, Tie-lines and Oflsets. 87 (128) It will easily appear from the sketch of Field-book No. 1,how much time and labor may be saved, or lost, by the mamaer otdoing the work. Thus, beginning at A, and measuiing 750 links,a pole should be left there, and the line to the right measured tc17 chains, or C, leaving a pole at as a new starting point byand by. Then from C measure 19 chains to A again ; then mea-sure from A to B, and from B back to the pole left at on themain line. i- (129) The example which will now be given shows part of theField-notes, the plat, (on a scale of 6 inches to 1 mile [1: 10,560]),and a partial calculation of the Filling up of a large triangle,the angular points of which are supposed to have been determinedby the methods of Geodesic Surveying. They should be wellBtudied.* Fig. 77
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectsurveying, bookyear18
