Winslow's Comprehensive mathematics : being an extensive cabinet of numerical, arithmetical, and mathematical facts, tables, data, formulas, and practical . Rule. — Take R in the dividers, or beam compasses, and fromany suitable centre, 0, describe an arc, it v, to any sufficient , with r the radius, and the same centre, describe an arc par-allel to the former, r n, to any sufficient length; then draw a rightline from the central point to the outer arc, and cutting the arcs,as at r and it. 346 PATTERN Suppose, now, for example, that the arcs are drawn to radii onc
Winslow's Comprehensive mathematics : being an extensive cabinet of numerical, arithmetical, and mathematical facts, tables, data, formulas, and practical . Rule. — Take R in the dividers, or beam compasses, and fromany suitable centre, 0, describe an arc, it v, to any sufficient , with r the radius, and the same centre, describe an arc par-allel to the former, r n, to any sufficient length; then draw a rightline from the central point to the outer arc, and cutting the arcs,as at r and it. 346 PATTERN Suppose, now, for example, that the arcs are drawn to radii onceand one-third the diameters of the bases; that the radius of thegreater arc is 16 inches; and that you wish to take out a patterncontaining one-fifth part of the side of the vessel. Referring to the table, column R = 1^ A andagainst \ in the column of por-tions, you find .4669; and16 X -4669 = inches, thechord required. Take inches in the dividers oron the square, and from thepoint R, with that measure, cutthe greater arc as at v, and fromthe new-found point, i>, draw aright line to the central pointoy and cutting the lesser arc,as at n; then will R v n r bethe pattern sought. On the contrary, suppose you have drawn the arcs to radii fourtimes the diameters of the bases, that the diameter of the lesser baseis 5 inches, and that a pattern containing one-third part of the lat-eral portion of the vessel is required : then, by the table, columnR — 4D ; and against \ in the column of portions, the const
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectmathematics, bookyear
