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 . e course of Mr. C. in 1789, N. 86° 18E., allowed a change of 1° 12, which was wrong by our calcula-tion, which gives only about 27, and was deduced from three dif-ferent records. Mr. D. in 1815, ran a course of N. 88° 30 E,calUng the increase of variation since 1789, 2^ 12. Our estimatewas 2° 18, the difference being comparatively small. Ou
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 . e course of Mr. C. in 1789, N. 86° 18E., allowed a change of 1° 12, which was wrong by our calcula-tion, which gives only about 27, and was deduced from three dif-ferent records. Mr. D. in 1815, ran a course of N. 88° 30 E,calUng the increase of variation since 1789, 2^ 12. Our estimatewas 2° 18, the difference being comparatively small. Our con-clusion then is this: the second surveyor retraced correctly the lineof the first: the third surveyor ran out a neiv and incorrect line: andthe fourth surveyor correctly retraced the line of the third, and foundhis marks, but this line was wrong originally and therefore wrongnow. All the surveyors ran their lines on the supposition that theoriginal due East and West line meant East and West as theneedle pointed at the time of the original survey. The preponderance of the testimony as to old land marJis agreedvnth the resvdts of the above reasoning, and the decision of theCourt was in accordance therewith. 11 210 COMPASS SURVEYING. Fig. 211. In the above figure the horizontal and vertical Hnes representtrue East and North lines ; and the two upper lines ruiming from leftto right represent the two lines set out by the surveyors and in theyears, there named. (323) Remedy for the evils of the Secular ehan^e. The only complete remedy for the disputes, and the uncertainty ofbounds, resulting from the continued change in the variation, isthis. Let a Meridian, i. e. a true North and South line, be estab«lished in every town or county, by the authority of the State ;monuments, such as stones set deep in the ground, being placed ateach end of it. Let every surveyor be obliged by law to test hiscompass by this line, at least once in each year. This he coulddo as easily as in ta
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectsurveying, bookyear18
