The Curve of Force
Valuable Curves
Turning to [Figure 70], [Plate 20], we find that whenever nature desires to support a weight she is inclined to use a peculiar curve seen at F. Possibly through continued observation the eye has associated this curve with strength or supporting power. [Figure 71] has detailed this curve. It is found to consist of a long, rather flat portion with a quick and sudden turn at its end. The curve is known to designers as the Curve of Force and is most valuable in all forms of enrichment. Designers even in early ages used it in some form as will be noted from the fragment of Greek sculpture in [Figure 72]. Its beauty rests in its variety. A circle has little interest due to its rather monotonous curvature. The eye desires variety and the curve of force administers to this need and gives a sense of satisfaction. As designers on wood, how are we to utilize this curve for purposes of outline enrichment?
An Approximate Curve of Force
For approximate similarity of curvature an ellipse constructed as shown in [Figure 73] will be found convenient. By drawing several ellipses of varying sizes upon sheets of tin or zinc, a series of templates of utmost practical value may be formed and used as was done in securing the curves of force in [Figures 74] and [75]. If the rail or shelf is longer than the post, measured downward from the rail to the floor or to the next shelf, the ellipse should be used with its major axis placed in a horizontal position, [Figure 75]. If, on the contrary, the post is longer than the shelf the ellipse should have its major axis in a vertical position, [Figure 74]. [Figures 76] and [77] show other instances of the use of the approximate curve of force. Many similar practical applications will occur to the designer.
Mouldings
We have classed the bracket as a link connecting a vertical and horizontal structure. Mouldings may likewise be considered as links connecting similar horizontal or vertical surfaces by bands of graded forms. Inasmuch as they effect the outline they are considered in this chapter. As the mouldings are to assist the eye to make the jump from one surface to another by easy steps, the position from which the mouldings are to be seen determines to some extent their design.
Plate 21
[Figure 78] shows the relation of the spectator to three types of mouldings at A, B, and C. The top or crown (A) is to be seen from below. On a large project the angle of the mouldings with the body of the object should be approximately 45 degrees. The intermediate moulding (B) is lighter than the crown and forms a transitional link that may be seen from either above or below. The lower or base moulding (C) is the widest member of the group as demanded by our sense of stability. It is seen from above. Both for sanitary and structural reasons it projects but slightly from the base. With this grouping in mind it is needless to say that a faulty moulding is one, some portion of which, hidden by intervening moulding, cannot be seen by the spectator.
Architectural design and history have formulated a series of curves, geometric in character, that are regarded as standards in the Industrial Arts. Some of the more prominent curves with their constructions are shown in [Figure 79]. The horizontal divisions are analyzed in accordance with Rules 2a and 2b. It is noticed that the Scotia possesses a curve having the shape of the curve of force, while the two Cymas are saved from monotonous division by means of their reversed curves, illustrating the contrast of direction. The curves of [Figure 80] are excellent lines for freehand practice in designing mouldings and will develop the principle of continuity of curvature or the smooth transition of one curve into the next.
Continuity and Contrast
To keep this continuity from the monotony of a Marcel Wave it is customary to break continuous curves by a fillet such as a straight line as shown at D, [Figures 81], [82], and [83]. When the desired outside diameter has been reached, contrast of direction is necessary and pleasing as a return, [Figure 82]. A glance at the curves so far considered will quickly determine whether they are fitted for the crown, intermediate or base mouldings. A curve should join a straight line with either a tangential or right angle junction, which makes for positiveness in contour expression.
Grouping of Curves
Application of these curves to outline enrichment for wood turning projects is to be governed by a strict adherence to Rules 2a or 2b, otherwise confusion and lack of unity will result. [Figure 83] shows a major grouping under Rule 2b with the subdivisions and minor curves arranged under Rules 2a and 2b. [Figure 84] shows a disregard for rules and the result is an undesirable monotony of contour. If smooth and even continuity of curvature is given considerable thought, together with that for systematic grouping and variety, a pleasing result from wood turning (a much abused but pleasing form of outline enrichment) may be secured. Figures [85] and [86] are illustrations from the industrial field with moulding curves grouped, following and supporting the structural lines of the object. The columns in [Figure 86] might, however, be advantageously reversed.
Figure 85.—Modern Candlesticks
Courtesy of Berkey and Gay
Figure 86.—Modern Book Trough
Materials
Large objects designed to be seen from a distance require larger space divisions for their mouldings than do small objects seen from a nearer point. Material affects the curve somewhat. Smaller mouldings are more suited to the expensive woods like mahogany while larger curves may be used in pine or oak.
Evolution of Enriched Outline Design
We now have at our command a number of interesting and serviceable curves suited to the material. [Plate 22] is a sheet of applications. [Figures 87] to [94] deal with the book-rack end and in this, as in the [initial chapter], architecture is referred to as the source for many laws of industrial design. It has seemed wise to illustrate some of these important parallels as follows:
We will assume the type of joint construction of the book-rack end as settled and the question of enrichment to be under consideration.
[Figure 87] is a simple primary mass without enrichment. It is comparable to the plain box-like structure with monotonous outline and without interest. The eye follows the outline in the direction of the arrows, pausing at the square corners, which interrupt a free movement by a harsh right angle. The base (an appendage) repeats in each instance the lines of the primary mass.
[Figure 88]. Round corners, by freeing the design from the right angles, accelerate the eye movement and give a sense of added interest and grace to the contour.
[Figure 89]. The cornice of a building suggests a similar arrangement which may be added to the primary mass. It adds the element of contrast of direction and variety of widths.
Variations
[Figure 90]. The main primary mass of a building with two equal appendages will suggest the enrichment of the outline in sympathy with three vertical divisions. Rule 3b. The rounded corners again assist the eye to travel freely around the contours, thus giving a sense of unity to the entire form.
Plate 22
Figures 101 and 102
[Figure 91]. The pediment of a Greek temple with the interest centered at the top of the pediment (x) causes a similar concentration of interest in the book-rack end. The slight inclination of the sides supplies variety of widths. The architect considers an object with the interest centered in this manner in the upper portion, as possessing more individuality than a motive with purely horizontal lines across the top boundary.
Figure 102a
Courtesy of Berkey and Gay
Figure 103.—A Modern Telephone Stand and Stool
[Figure 92]. In this figure the curved inclination facilitates the upward movement of the eye, at the same time supplying variety of width.
[Figure 93]. The addition of an appendage to the outline of the Greek temple suggests a slight drop or variation in the top edge of the book-rack end which gives increased interest and grace through variety.
[Figure 94]. Contrast of direction is supplied in this suggestion but it is questionable whether we are adding much to the interest by the corner.
Courtesy of Berkey and Gay
Figure 104.—Modern Chair
Courtesy of Berkey and Gay
Figure 105.—A Modern Serving Table
[Figures 95] to [98] are variations of one theme, the foot stool, and [Figure 99] adds suggestive designs for rails. D in [Figure 99] shows the enrichment line cut to a depth which threatens the structural value of the rail. This is corrected in [Figure 103]. [Figure 100] is an application of the curve of force to a chair leg B, with other possibilities at A and C. Numerous applications of the varied curves under consideration are found throughout this sheet.
Figure 105a
Courtesy of Berkey and Gay
Figure 106.—Sheraton Table
Before closing with enriched outlines it is well to consider flagrant violations of this enrichment now on the market. [Figure 101] shows a typical example of complete lack of unity and simplicity. It is a type of design often associated with cheaply constructed furniture. It is an ornate parody on outline enrichment. The curves of extravagance are well shown in [Figure 102] where large bulbous curves with no systematic grouping combine disastrous waste of material with lack of grace or lightness. It is excellent practice to redesign such examples as those shown in [Figures 101] and [102] with special reference to Rule 5c.
Rule 5c. Outline enrichment, by its similarity, should give a sense of oneness or unity to the design, binding divergent members together.
Illustrations [103] to [106] are typical forms of present day outline enrichment. Limitations of space will not permit reference to the use of Period furniture. Sheraton and Hepplewhite designs are most adaptable for school uses as may be seen by comparing the Sheraton desk ([Figure 106]) with the foot stool in [Figure 96].
INSTRUCTION SHEET
[Figure 83] and [Plates 22] and 23 are indicative of what might be obtained from a class. The problem represented on Plate 23 is advantageously colored with the intended stain and with a small section of side wall and trim visible. See [Chapter 16], [Figures 458] to [463]. [Figure 102a] shows the method of enlarging a design into a full size working drawing for shop purposes.
SUMMARY OF DESIGN STEPS
(a) Draw the primary rectangle.
(b) Subdivide the rectangle into vertical and horizontal divisions.
(c) Determine parts to be treated by contour enrichment.
(d) Determine method suited to the project: wood turning, moulding, etc.
(e) Group the wood turning curves under a definite system included under Rules 2a and 2b. Group the mouldings under crown, intermediate, and base classifications. Add this enrichment to the primary mass or make other simple variations that will not destroy the unity of the project.
(f) Dimension and otherwise prepare the drawing for shop use.
(g) Construct the project.
Note.—If the designer is not properly equipped to prepare his own mouldings, he should consult moulding catalogs or the stock of some local lumber company.
ADDITIONAL SUGGESTED PROBLEMS
Design a wood pedestal with the curves grouped into three horizontal divisions.
Design a hall table 2 feet 10 inches high and add simple contour enrichment.
SUMMARY OF RULES
Rule 5a. Outline enrichment should be subordinated to and support the structure.
Rule 5b. Outline enrichment should add grace, lightness, and variety to the design.
Rule 5c. Outline enrichment, by its similarity, should give a sense of oneness or unity to the design, binding divergent members together.
REVIEW QUESTIONS
1. State nature and need of enrichment.
2. What two forms of enrichment are commonly used in industrial arts design?
3. What four qualities are added to industrial design by contour enrichment?
4. What disturbing elements should be guarded against in the application of contour enrichment?
5. Describe the curve of force and its function in the contour enrichment of wood.
6. What are mouldings? Name three types of mouldings, their positions with relation to the eye level, and some curves used in their design.
7. Give examples of curves of continuity and contrast. By what means should two contrasting curves be separated?
8. How should a curve join a straight line?
9. Explain the grouping of contour curves in wood turning projects similar to a round leg or candlestick.
10. Present five designs for book-racks, enriched by changes of the contour. Give architectural cross references for each design.
11. Present three well designed table or chair legs and top and bottom rails and assemble one of these in a design.
Chapter VII
ENRICHMENT OF THE CONTOURS OR OUTLINES OF DESIGNS IN CLAY
Need of Enrichment
In the medium we are now about to consider there is a tendency for the enthusiastic beginner to over-elaborate the outline into meaningless forms. This possibly is due to the ease with which clay is manipulated. It would be well then to ask two questions before starting with the work of enriching the simple structure. First, why should it be enriched—is there a positive gain by so doing? Second, (if the decision is favorable to enrichment) where should it be enriched? Let us co-ordinate the parts to assist in this process.
Parts Differing in Function
Rule 5d. Parts of one design differing in function should differ in appearance but be co-ordinated with the entire design. As a suggestion to guide one in enriching an object it is necessary to consider that parts differing in function may differ in appearance, but as members of one family they should still be related to the whole. For example, a spout, handle, and lid may differ in design from that of the body of a pitcher because they differ from it in function. Again, the rim and foot of a vase may be slightly changed or individually accented because of their respective duties. The base and holder of a candlestick may vary in design from the central part or handle, as each has a special function to perform. This rule of the change of appearance with the change of functional service (Rule 5d), is found throughout architectural design. The variation in design in the base, shaft, and capital of a column is possibly one of the most common examples. While differing in function they still must have unity and "hold together."
Unity
These functional parts of one design, differing in service rendered, form centers of construction and may receive emphasis in outline enrichment. Corners and terminal points are likewise available for decoration and will be discussed at length later.
Figure 107.—Clay Outline Enrichment in the Rookwood Potteries
Enrichment in clay and metal generally means a substitution of curved for straight lines in the enriched portions of the design. These curves have the ability to impart grace, lightness, and variety to an object provided they are based upon constructive features of the problem. They must have a unit of measurement and must likewise be appropriate to the material. It is therefore necessary to deal with clay in this chapter and follow with a consideration of metal in [another chapter].
In [Figures 109] to [123], [Plate 24], we have a number of examples of variation of practically the same primary enclosing rectangle. [Figure 108] represents a "squarely" proportioned circular bowl lacking both refinement of proportion and enrichment. [Figure 109] has added refinement of proportions. [Figures 110] and [111] have introduced an outline enriched to the extent of a simple curve. The base is the dominant width in the first, and the top dominates in width in the second. The outline in [Figure 112], while similar to [110] for a portion of its length, departs at a stated point and by curving in toward the base supplies more variety to the contour. We have already said that this outline curve should have a unit of measurement and by referring to Rules 2a and 2b we are able to formulate the following:
Unit of Measurement for Curves in Outline Enrichment
Rule 5e. In cylindrical forms outline curves with a vertical tendency should have their turning points or units of measurement in accordance with the horizontal divisions of Rules 2a and 2b. [Figures 112] and [113] have as their unit of measurement two horizontal spaces formed in accordance with Rule 2a, while [Figures 116] and [117] have still more variety by the addition of a compound curve with its turning points or unit of measurement based upon Rule 2b. [Figures 114] and [115] with outlines similar to those in [Figures 112] and [113], respectively, have an additional enrichment, the foot and rim accentuation.
Accentuation of Functional Parts in Clay
The new element of enrichment consists of accenting by adding to the design a modeled rim and a base or foot, as it is technically known. This not only strengthens the structure at these two functional points but, by adding a small section of shadow, it tends to break up the surface, [Figure 127], and add to the variety of enrichment. [Figures 124] to [127] show the building processes connected with this interesting and constructive addition.
Appendages
[Figures 116] to [119] show variations of the preceding figures while [Figures 120] to [123] introduce the appendages to preceding figures. As in the designing of all appendages, discussed in [Chapter V], it is the designer's intention to balance spout and handle to avoid a one-sided or top-heavy appearance.
One of the principal difficulties that confronts the amateur designer is the failure to secure variety while retaining unity. This is largely due to a lack of ideas upon the subject and a marked lack of systematic development of one theme.
Plate 24
Systematic Development of Outline Enrichment in Clay
Attention is directed to the diagram in the lower portion of [Plate 24]. The idea is to start with some simple form in columns A, B, C, D, E, F, [Figure 128]. [Figure 129] introduces two horizontal divisions. Rule 2a. The black portion is the dominant section. Notice the change in outlines based upon this division. [Figure 130] raises the division point of the two subdivisions into the upper half of the object. This brings out the need of an accented foot which is, however, not of sufficient prominence to be considered as a horizontal spacing. [Figure 131] raises the horizontal division points, again causing the introduction of a larger foot and now qualifying it as a division of the whole mass. This then makes our design a three-division problem, Rule 2b, and places it under the restrictions of Rule 5e.
The feet of all of the bowls have been systematically decreased in width by the converging lines C-C while the tops have been maintained constant in width. By this simple diagram an infinite number of designs may be formed and the choice of selection from the series, thoughtfully exercised, will supply the ideal bowl, ready to be translated into a full size working drawing. It is not the idea, however, to guarantee a perfect design in each one of these divisions as that would be practically impossible, but we have systematically applied a method of determination for stimulating the imagination. A series of articles by F.H. Rhead in the Keramic Studio first suggested the system of development by means of graded rectangles.
Candlesticks
[Plate 25] shows a further elaboration of the succeeding themes. The candlestick series, [Figures 132] to [138], introduces two or three-space division problems with contour turning points at A, Rule 5e, and with accented or embryonic feet and rims. The change from the purely functional and unenriched member of [Figure 132] through the series shows the enrichment changing slightly to meet the needs of the three functional parts: the base, the handle, and the candle socket. Rule 5d.
Containers
[Figure 139] shows a series of illustrations representing variations for containers. The first figure is without enrichment, followed by variations of the outline in the manner already suggested.
Pourers
[Figure 140] indicates a series of pourers with the least attractive design on the left end. This unsatisfactory design is found, upon analysis, to be due to centrally placed horizontal division violating Rule 2a. The design of the appendages in this series will again be found to conform with the rules in [Chapter V]. The units of measurement for the curves may be readily ascertained from observation.
Plate 25
Similarity with Varying Primary Masses
[Figure 141] is useful for the following purpose. It is desirable at times to develop a number of similar forms for a set, with a gradually increasing ratio of proportions, either in height or width. [Figure 141] shows how the height may be increased while maintaining a common width. Notice the gradual proportionate increase of the height of the neck A-B as well as that of the body. The line X is of the utmost value in ascertaining the height of the intermediate bowls. The eye should now be so trained that the height of the neck A-B on the last bowl can be readily proportioned by eye measurement to that of the first bowl. A line similar to X will give the intermediate points.
[Figure 142] varies the width in a similar manner. Notice the gradually decreasing distances C-D-E-F, the spaces for which may be determined by the eye.
Plate 26
INSTRUCTION SHEET
[Plate 26] suggests the sequential progression of steps leading to the potter's working drawing.
SUMMARY OF DESIGN STEPS
(a) Draw the primary rectangle.
(b) Add limits of functional parts: handle, spout, cover, etc.
(c) Establish unit of measurement for primary rectangle contour curves.
(d) Design contour of primary mass and add the appendages to it, observing the rules pertaining to appendages and unit of measurement.
(e) Dimension and otherwise prepare the drawing for the potter's use. This includes the planning of a working drawing, one-eighth larger in all directions than the preliminary design, to allow for the shrinkage of the clay body. The working drawing should also be in partial sections to show the construction of the interior of the ware.
SUGGESTED PROBLEM
Design a teapot, tea caddy, and cup showing a common unity in contour design. ([Plate 82].)
SUMMARY OF RULES
Rule 5d. Parts of one design differing in function should differ in appearance but be co-ordinated with the entire design.
Rule 5e. In cylindrical forms outline curves with a vertical tendency should have their turning points or units of measurement in accordance with the horizontal divisions of Rules 2a and 2b.
REVIEW QUESTIONS
1. Give and illustrate the rule governing the change in the appearance of the design with the change of functional service.
2. What is the aesthetic value of curves in outline enrichment?
3. Correlate the rule governing the unit of measurement for vertical contour curves with the rules controlling horizontal divisions.
4. Show, by a diagram, the method of systematically varying the contours of circular forms: (a) by changing the horizontal divisions; (b) by varying the proportion of the primary mass.
5. What is the value of accenting the functional parts in clay design?
Courtesy of James Milliken University
Figure 142a.—Outline and Surface Enrichment in College Pottery
Plate 27
Chapter VIII
ENRICHMENT OF THE CONTOURS OR OUTLINES OF DESIGNS IN BASE AND PRECIOUS METALS
Enrichment of the Base Metals—Iron, Copper, Brass, Bronze
The contours of clay forms are generally free to follow the curves and take the direction dictated by the knowledge and taste of the designer. Metal outlines are more restricted in this respect. Metal is frequently associated with service and consequently its design is often governed by its intended use. For example, if we were to design a metal drawer pull for a buffet, it would have to be considered in relation to the character and shape of the buffet. Again, the screws with which it is attached to the buffet would influence its outline design. It is, in other words, a dependent outline.
Free and Dependent Outlines
To distinguish between an unrestricted outline and one bound by other considerations we will term the restricted outline a dependent outline, for its enrichment must be related to other forms either within or without its surface. A free outline on the other hand is one in which the designer is free to use his ideas unrestricted by any other outside consideration, except service and design consistent with the material.
In order to emphasize the nature of a dependent outline we have Rule 5f. Dependent outline enrichment should be related to essential parts of a design and influenced by their forms and functions; it must be consistent with the idea of the subject.
Enrichment of Edges
We will start with the simplest form of outline enrichment of base metals, the decoration of an edge. It is contrary to the laws of service to leave sharp edges on articles intended for intimate household use, except where cutting edges are required. The rounding of sharp edges is likewise dictated by the laws of beauty. The transition from one plane surface to another is assisted by a rounded edge, as the eye takes kindly to the softened play of light and shade.
This gives us the simplest form of enrichment—the beveled, chamfered, or rounded edge, [Figures 143] and [144], [Plate 27]. The rim of a thin 18-gauge plate is likewise improved and strengthened by lapping the edge as shown in [Figure 145], giving the rounded effect shown in [Figure 144].
Enrichment of Functional Parts
There are six important functional parts with which we are brought into common contact in industrial design of base metals. There are many more, but these are the most common and consequently are of the utmost importance to the designer as design centers. These parts are itemized as follows: (1) Corners, (2) Appendages, (3) Intermediate Points, (4) Terminals, (5) Links, (6) Details. As the decorative treatment of each part varies with the functional duty, Rule 5d, separate treatment and consideration of each part will be necessary.
Enrichment of Corners
Corners, as extreme turning points of a design, are often found convenient for the location of screw holes, rivets, etc. These important construction elements become prominent functional parts of the design and by custom and the laws of design, Rule 5d, they are capable of receiving outline enrichment. But the contour of the corner must be related to the screws or rivets, particularly if they are near the edge, hence our outline becomes a dependent outline and as such must be related to the rivets or screws by Rule 5f.
[Figures 146] to [149] show various arrangements of this type of design. The unity of the design is not lost, and the functional parts are enriched by contours related to the elements of service (rivets). [Figure 153] shows another but slightly modified example of the same laws applied to hinge construction. The enriched outline in this case is closely associated with the holes in the hinge. The hinges in turn must be related to the object for which they are designed. [Figure 150] gives a common example of corner enrichment by means of varying the edge at the corners, i.e., by rounding the tray corners.
Enrichment of Appendages
As appendages have distinct functional duties their design may vary as the design of the arm of the human figure differs from the head. Yet, as parts of the same body, they must fit the shape of the object to which they are attached. The candle holder and handle as appendages in [Figure 150] are designed in sympathetic relation by means of tangential and similar curves sufficiently varied to give the eye a feeling of variety in the design. The novel single flower holders, [Figures 151] and [152], with the glass test tube acting as a container show other possible forms of the appendage design. The first is informal while the second is formal, but both adhere to the first simple rules of appendage design. Rule 4a, etc.
Enrichment of Intermediate Points
Figure 156a.—Candlestick, Rendered by E.R.
The enrichment of center or intermediate points should be handled with great care and with a definite reason. Careless handling may cause the design to lack unity. [Figures 154] and [155] show a simple twist as enrichment. The serviceable reason for this is to obtain a grip at the point of the twist. Again, it varies the character of the straight edges and adds interest without loss of compactness or unity. If one is desirous of widening a vertical or horizontal rod, the enrichment made by welding a number of small rods together with a spreading twist gives a pleasing and serviceable handle. [Figure 156].
Plate 28
Enrichment of Terminals
Free and Dependent Contour Enrichment
As the public demands a happy ending to a story or a play, so does the eye demand a well-designed ending to a design. The part that terminal enrichment plays in industrial design is, therefore, to say the least, important to us as designers. [Figure 157] illustrates terminals in thin metal and is shown by courtesy of the School Arts Magazine from one of the articles by Mr. Augustus Rose. The outlines are in part dependent in character, controlled by rivets. Notice the change of curve as the function changes from the dependent curve of the rivet area to the free outline of the handle and again from the handle to the cutting blade; a functional change of marked character, but in thorough unity with the entire design. It is again emphasized that whether the design possesses a free or a dependent outline, or a combination of both types, all parts of the design must be held together by entire unity. The rivets are occasionally placed toward the edge and a domed boss is used to accent the center as is shown in [Figure 158].