4. Line

4 - 03 TYPES OF LINE

d. SPIRALS:
The purest and most universal form of motion is the spiral; the counter-clockwise spiral being the one found most often in nature - in seashells and in the growth of trees, in the seed heads of sunflowers, and in the DNA helix of the human genetic constitution. The seed head of the sunflower is a double spiral, in which the clockwise spiral intersects with a counter-clockwise one.

Like curves all spirals are not the same. The equiangular or logarithmic spiral of the elegant chambered nautilus is one type that is also seen in the ram's horns. It is interesting to note that the double spiral of the sunflower corresponds to the ratio of the Fibonacci Series: if you count the number of seeds in a clockwise spiral and those in a counter-clockwise spiral, the two figures will be that of a sequence in the Fibonacci Series.

The DNA helix has been directly translated into architecture, in the form of a spiral staircase. It has also inspired great works of architecture. Wright, in his later work has emulated the spiral of a seashell.

e. DIAGONALS:
The horizontal and vertical scheme, while being the clearest, and in many ways the most useful, has one major limitation - it cannot distinguish between things standing at rest, maintaining themselves in position, and being in motion. The diagonal lines depict experience of motion - people walking, animals running and birds flying - and this is when a human being, from his childhood, discovers the importance of oblique lines.

The diagonal is at variance with the pull of gravity, as well as with the sense of equilibrium in the mind of the spectator and the parallel sides of the usual pictorial format. It signifies things in the throes of change - acting or being acted upon; and, as change must occur in time and space (the two being important elements and constant companions), both time and space find expression in works of art and architecture.

The use of the diagonal can be traced to the sixteenth century friezes of Michelangelo, and also to Frank Lloyd Wright's architecture of the 1930s, when he based the design of certain houses on the angle of 120 degrees of the hexagon, instead of the conventional 90 degrees rectangle. The result was a much easier flow of space, eliminating sharp corners. In the 1940s, Wright's concept of plasticity and continuity of space and structure led him toward the circle. Finally, in the late 1950s, as though following the logic of organic and aesthetic geometry, he favoured the spiral, as in the Guggenheim Museum of New York.

Cubism, because it placed so much importance on the straight line and the articulation of movements in space by means of directional planes, led directly to a kind of painting in which diagonal action would be of unique importance. So, it is significant in Robert Delauney's paintings of the Eiffel Tower, in Marcel Duchamp's painting 'Nude Descending the Staircase’, and in Paul Klee's multiple perspectives.

f. DYNAMIC LINES:
Lines generate visual dynamism, either when the composition lacks a strong focal point, or when they are conspicuously informal. The result, in either case, is that the eye does not remain on any particular element of the composition, but oscillates between the various elements. Indistinct background- foreground compositions and those with many colours also reveal visual dynamism. Informal lines, made by ink-loaded twigs or by blowing spilled ink, create a peculiar kind of dynamism, a linear agitation that borders on chaos. The best example of dynamic lines seen in nature is the black and white striped zebra.

Diagonals or curves, expressed either two-dimensionally as lines or three-dimensionally as planes, can be considered as the form-equivalents of kinetic energy. These dynamic lines are described in terms of thrust: a) Point Thrust, as seen in the arrow, the column and the steeple; b) Centripetal Thrust, seen in the clock spring, the spiral seashell, in all spiral forms, natural or manmade, where energy uncoils from a centre; c) Pressure or Pneumatic Thrust, seen in a balloon, in ripe fruits and vegetables, eroded earth forms, sea creatures, the human skull and the head of the femur, the egg, and all forms that are the result of tensions fairly & evenly distributed; and d) Radial Thrust, seen in the wheel, in certain seed heads and in explosions. These kinds of thrust are often seen in combination with elements of potential energy; as in a tent, a clothesline or a suspension bridge, where the point thrust of the pole or the nylon is complemented by the catenary arc of the canvas, the line or the cables, or contrarily in the association of continuous and discontinuous patterns in the formations of mountains.