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 . (432) Problem. To measure an inaccessible distance, AB,when only one point, C, can be found from which both ends of theline can be seen. Consider CA Fi. and CB as distances to-be deter- ^rr -2^ mined, having one end them, as in Art. (427),by choosing a point D, from whichC and A are visble, and a point Efrom which
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 . (432) Problem. To measure an inaccessible distance, AB,when only one point, C, can be found from which both ends of theline can be seen. Consider CA Fi. and CB as distances to-be deter- ^rr -2^ mined, having one end them, as in Art. (427),by choosing a point D, from whichC and A are visble, and a point Efrom which C and B are C observe the angles DCA,ACBand BCE. Measure the distances CD and CE. Observe theangles ADC and BEC. Then in the triangle ADC, two angles andthe included side are given, to find CA ; and the same in the tri-angle CBE, to find CB. Lastly, in the triangle ACB -wo 9ideaand the included angle are Viaown, to find 292 OBSTACLES IIV ANGULAR SIRVEIING. [part vii
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectsurveying, bookyear18
