. A Recommendation of Hadley's Quadrant for Surveying, Especially the Surveying of Harbours, Together with a Particular Application of It in Some Cases of Pilotage. By the Rev. John Michell, B. D. F. R. S. . JlMipuUJc. • [ 73 ] the intended fegments•, but, if the angle, corre-fponding to the intended fegment, is to be neithergreater or lefs than 900, the point A, which bife&sthe line B C, will be the centre of the intendedfegment. Thus, if I would have the angle in the intendedfegment, to confift of 1200, I conftitute uponBC, at the point C, the angle DCB equal to300, the difference between 12
. A Recommendation of Hadley's Quadrant for Surveying, Especially the Surveying of Harbours, Together with a Particular Application of It in Some Cases of Pilotage. By the Rev. John Michell, B. D. F. R. S. . JlMipuUJc. • [ 73 ] the intended fegments•, but, if the angle, corre-fponding to the intended fegment, is to be neithergreater or lefs than 900, the point A, which bife&sthe line B C, will be the centre of the intendedfegment. Thus, if I would have the angle in the intendedfegment, to confift of 1200, I conftitute uponBC, at the point C, the angle DCB equal to300, the difference between 1200 and 900, and oilthe oppofite fide of C B from its correspondingfegment, becaufe it exceeds 900. Then with thecentre D, and radius DC, I defcribe the fegmentC 120 B, in every part of which the two pointsC and B will fubtend an angle of 120°. In like manner, if I would have the angle in theintended fegment to confift of 8o°, I conftitute uponBC, at the point C, the angle BCG equal to io°fthe difference between 8o° and 90% and becaufe theintended angle is now lefs than 900, I place G onthe fame fide of B C with its correfponding feg-ment. Then with the centre G, and radius G C,I defcribe
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