The Ionic Volute
Terminal Enrichment in Wrought Metal
As the Curve of Force was a valuable curve in wood construction, so we find it an equally valuable curve for wrought metal. Its recurrence again and again in industrial design leads us to appreciate its value in the arts. It is the Ionic volute handed down to us in its present form from the time of the Greeks, who developed it to a high state of perfection.
Curve of Beauty
While its geometric development is a tedious process, it may be easily constructed for practical purposes by the following method. In [Figure 159], P represents a small cylinder of wood, possibly a dowel. A strong piece of thread, or fine wire, is wrapped around the base of the dowel a number of times and a loop is formed in the free end. A pencil with a sharp point is inserted in the loop and the pencil and dowel are placed together on a sheet of paper. As the thread unwinds from the dowel the point of the pencil will describe a volute which may be developed indefinitely. It will be noticed that no corresponding parts of the curve are concentric and it thus has constant variety. It has been termed the Curve of Beauty and is found in nature in the wonderfully designed shell of the nautilus.
It is advisable to form several templates for the volute out of bent wrought iron, of different sizes, and to practice drawing the curve many times to accustom the hand and the eye to its changes of direction. The "eye" or center portion is sometimes terminated by thinning and expanding in the manner shown in [Figure 160].
Plate 29
Greek Scroll
One form of application of the volute is shown in the terminal points of the candlestick in [Figure 161]. It is here shown combined with the second volute in the form of a reverse curve. In [Figure 162], it has been combined with a smaller but reversed volute at the upper end. The entire and combined curve is commonly known as a Greek Scroll. In [Figure 163] the Greek Scroll has been combined with the reverse curve of [Figure 161] to form a portion of the bracket. In this figure we find the familiar curve of force faithfully serving its function as a supporting member for the top portion of the bracket.
Enrichment of Links
A link is a convenient filler in connecting parts of a right angle. It likewise serves as a brace in connecting several disconnected parts and is useful in maintaining the unity of a design. [Figure 164] shows a common form of link with its ends thinned and expanded as shown in [Figure 160]. This construction may, however, be disregarded as it is technically quite difficult to accomplish.
Enrichment of Details
Details are the smaller portions of a design and are similar to the trimmings and minor brackets of a building in relative importance. They enter to a considerable extent into wrought metal grille design, and are generally formed of the link, Greek scroll, or the Ionic volute, so as to be in harmony with the other parts of the design outline. Rule 5f. Their presence and use may be readily detected on [Plate 28].
Rule 5g. A curve should join a straight line with either a tangential or right angle junction.
Summary of Wrought Metal Free Outline Enrichment
As we are now familiar with continuity in wood moulding curves we should feel, in reviewing the figures in this chapter, the value of flowing continuity and tangential junction points (Rule 5g) necessary in wrought metal enrichment. The curves that we have considered are adapted to the materials and a comparatively large and new field of design is opened to the designer through a combination of curves mentioned. [Plate 30] is self-explanatory and brings out the general application of the foregoing principles as applied to cast bronze hardware. It is interesting to notice the change of enrichment paralleling the change of function as outlined in Rule 5d.