. A treatise on surveying and navigation: uniting the theoretical, the practical, and the educational features of these subjects. the results of the multiplications to two places of decimals ; that is, to the nearest link, which is a degree of accuracy sufficient for all practical purposes. We are now prepared to estimate the areas of the following generalsurveys, given as examples .1. In May, 1845, the following measures of a field were at the western-most point of the field ; thence ff. 20° 30E. 5 chains 83 links; thence S. 79° 45^. 10 chains 15 links;thence S. 27° 30 W. 9 ch
. A treatise on surveying and navigation: uniting the theoretical, the practical, and the educational features of these subjects. the results of the multiplications to two places of decimals ; that is, to the nearest link, which is a degree of accuracy sufficient for all practical purposes. We are now prepared to estimate the areas of the following generalsurveys, given as examples .1. In May, 1845, the following measures of a field were at the western-most point of the field ; thence ff. 20° 30E. 5 chains 83 links; thence S. 79° 45^. 10 chains 15 links;thence S. 27° 30 W. 9 chains 45 links ; thence JV. 63° 15 chains 28 links ; thence K 15° 30 W. 1 chain and 4 links, to theplace of beginning; required the area. It is not absolutely necessaryto make a plot or figure of thefield, but for the sake of per-spicuity, it is best to do so ;yet no reliance is placed on theaccuracy of the constructedfigure. We perceive by the figure,that there are two south areas,bBCc, and cCDd; and threenorth areas, eEdD, AeE, andABb. Let the reader observe thatall the north areas are on theoutside of the MENSURATION OF LANDS. 97 AB Bearings. Dis. N. s. E. W. ! M. D. JS. area*. g; arteas. 30E. BC 9° 45 £. CD °30W. DE EA Area in acres, )) The operator can rely on therule used in the last operation,whatever be the number of sides,or whatever be the shape of thefigure, provided that the lines areright lines, from one angular pointto another. In case of re-entering angles,like HI A, represented in the ad-joining figure, a portion of thefigure Air, is reckoned twice. Butthis is corrected by the subtractivespace HIih, which includes notonly the exterior portion hHIA,but also the whole a
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Keywords: ., boo, bookcentury1800, booksubjectnavigation, booksubjectsurveying
