The American house-carpenter; a treatise upon architecture, cornices and mouldings, framing, doors, windows, and stairs. Together with the most important principles of practical geometry (1852)
Hatfield, R. G. (Robert Griffith), 1815-1879 · New York : J. Wiley · leaf 65
he arc, j i ; upon h and/, with h k for radius, describe the arcs, j k and I i; this willcomplete the figure. This is a very near approximation to an ellipsis; and perhaps nomethod can be found, by which a well-shaped oval can be drawnwith greater facility. By a little variation in the process,… … 122.— To draw a tangent to an ellipsis. Let abed, (Fig.38,) be the given ellipsis, and d the point of contact. Find thefoci, (Art. 115,)/and/, and from them, through d, draw/e andf d; bisect the angle, (Art. 77,) e d o, with the line, s r ; then5 r will be the tangent required.
Carpentry · Architecture
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.