The American house carpenter. A treatise on the art of building. Comprising styles of architecture, strength of materials, and the theory and practice of the construction of floors, framed girders, roof trusses, rolled-iron beams, tubular-iron girders, cast-iron girders, stairs, doors, windows, mouldings, and cornices; together with a compend of mathematics. A manual for the practical use of architects, carpenters, stair-builders, and others (1880)
Hatfield, R. G. (Robert Griffith), 1815-1879, Hatfield, O. P., ed · New York, J. Wiley & sons · leaf 511
meanProportional.—Let ABC {Fig. 294) be a semicircle. FromC, any point in the curve, draw a line to A and another toB\ then ABC will be a right-angled triangle {Art. 352).Draw the line CD perpendicular to the diameter A B;then CD will divide the triangle ABC into two triangles.A CD and CBD, which… … to its former position, the point B describing the curveB F, and the point C the curve CE, and each forming aquadrant or angle of ninety degrees. Since these pointshave revolved ninety degrees, therefore the three lines ofthe triangle 6^Z>have revolved into a position at rightangles to that…
Carpentry · Architecture · Building
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
