Plate 52. Drawing the Ionic Volute, by Davile and Goldmann

In Davile's method, the intersecting points of the volute windings are to be laid off on the radial axes, the length of the radial lines being found from the geometrical proportionals as given in the diagram at the left, in which the lines Bl, B2, etc., coincide with the same designated lines in the elevation. The center for the 1st arc 1-2 is at the intersection of two arcs whose radii are equal to A. B. and whose centers are at 1 and 2. This operation continued will complete the volute winding. The manner in which the arcs connect with each other, however, is slightly imperfect, as the radius at the finish of any arc does not fall exactly over the radius at the beginning of the next arc.

The method of Goldmann is similar to one of those given on Plate 51, but overcomes the faults of the one on that plate inasmuch as the 3 windings consist of 12 quadrants and the starting and ending points of the same are easily ascertained from the nature of the scheme. At the left-hand lower corner of the plate is given a diagram* for establishing the center points of the inner line of the spiral which can also be used for the volutes of Palladio and Vignola.

*The points 1, 5, and 9 under C correspond to the same points of the diagram in the eye, and the points b, c, and d under B correspond to the same points of the diagram in the eye and establish the squares (shown by dotted lines therein,) the corners of which are the centers for the inner spiral.— ED.