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 . where any other fence, or road, or other line, crosses or meetsit, and take their bearings. Take the compass to the end of thisfirst bounding line ; sight back, and if the back-sight agrees, takethe bearmg and distance of the next bounding Hne ; and so proceedtill you have got back to the point of starting. (253) Where speed is more importa
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 . where any other fence, or road, or other line, crosses or meetsit, and take their bearings. Take the compass to the end of thisfirst bounding line ; sight back, and if the back-sight agrees, takethe bearmg and distance of the next bounding Hne ; and so proceedtill you have got back to the point of starting. (253) Where speed is more important than accuracy hi a sur-vey, whether of a line or a farm, the compass need be set only atevery other station, taking a forward sight; from ihe 1st station tothe 2d ; then settmg the compass at the 3d station, takmg a backBight to the 2d station (but with the north point of the compass al-ways ahead), and a fore-sight to the 4th; then gouig to the 5th,and so on. This is, however, not to be recommended. (254) Field-notes, The Field-notes of a Farm survey may bekept by any of the methods which have been described with lefer-ence io a Line survey. Below are given the Field-notes of thegame field recorded by each of the methods. First Method. Fig. 152 COMPASS SURVEYING. [part m Second TJdrd Method. Method. 0(1) -(1)- ^ o CD to COCO ^ to 0(5) ^ ^ -(5)- o LO -hM- to CO CO ^ -hw CQ S! 1 ( )(4) CO 1 m p4 -(4)- o G<l lO c4 F^ QQ t- C )(3) tO m p4 -(3)- o CO 05 00J25 tH CO 0(2) GO m ^ o O -(2)- CO 52^ m 0(1) to CO ^ -(1)- Fourth Method. BEARINGS. DISTANCES. 1 2345 N. 350 8310 570 34|°
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectsurveying, bookyear18
