This is expressed in the geometry of the plan: its internal organisation being derived from the sacred geometry of the Vesica, which liberates the square, the equilateral triangle, the rhombus, the hexagon and the octagon — all of which are key figures in the design. The rectangle which determines the centres of the two formal basins also emerges from the Vesica and is projected from the common base of the equilateral triangles. The arc of the northern foreshore of the central formal basin has as its centre the Capitol while the plan geometry is extended to the peripheral areas ofthe central city and unified by means of hexagons and octagons organised along meridians radiating from Capital Hill. Walter Griffin's comment that 'the importance of such an orderly arrangement is very great and can only be appreciated from a city of great heights' reveals that an abstracted geometrical clarity and order was a crucial objective irrespective of the experience on the ground. In many ways, the City and Environs drawing can be interpreted as an abstract composition based on a symbolic, geometrical language of the square, the circle and the triangle,- a language that underpinned much of the development of modern abstract art.
Each of these forms — circle, triangle and square -— has a specific symbolic function within the iconographic tradition emanating from sacred geometry. The circle has always been a symbolic representation of the heavens, the spiritual and the unmanifest form of the cosmos. In alchemical symbolism the circle stands for the spiritual property of matter whereas the square represents the physical properties of matter, the earth and man's relation to it. The progression or transmutation from the circle-triangle to the square can be interpreted as symbolising the processes of creation in the cosmos or nature and also of the formation of crystals. This concept of the 'geometrical' construction of the crystal seems to be based on an esoteric interpretation which, at that time, was undergoing a revival through Theosophy.
The triangle is also a form which has a rich and arcane symbolism, as observed earlier. In Christian iconography it represents the Holy Trinity and in other religions is a common symbol for the Godhead. In material terms, which concerned the Griffins, the triangle was representative of the active and inactive forces of creation: in alchemical terms, the triangle with apex upwards — active — is the symbol for fire,- and with the apex downwards — inactive — it is the symbol for water. In The Ancient Science of Geomancy Nigel Pennick notes that when two equilateral triangles are joined base-to-base.
The disparate elements of the universe can be said to be reintegrated into the primordial whole'. This combination constitutes the fundamental order of the Canberra plan. Therefore, in geomantic terms as interpreted by Pennick, the geometry of Canberra, emanating from the Vesica, can be regarded as an abstract expression symbolic of the processes of creation underlying the order of the universe, the transmutation of the spiritual into the physical constituents of the universe.
Without consideration for scale, the Canberra plan can be perceived as a series of interrelated circles, triangles and squares/rectangles or, put another way, it represents the transmutation of the circle to the triangle to the square. The circle is paramount in the Capital Hill geometry with the three interconnections producing a double Vesica. In the original design it is repeated in the three formal basins while, on a more subtle plane, it permeates the total design derived from the original Vesica. The orifice contains the equilateral triangles base-to-base, the nodal points being Capital Hill, City Hill, Mount Pleasant and Mount Ainslie. The square is derived from the cardo-decumanus crossing of the land and water axes, that is, the quartering of the plan. As Walter Griffin appreciated, from a good elevated vantage point such as Mount Ainslie or Black Mountain, the design can be perceived as an abstract progression from the circle (Capital Hill), to the triangle {parliamentary triangle), to the square (the land and water axes). This sense of transmutation is reinforced by the hexagonal and octagonal street systems throughout the plan as these forms flower from the circle, triangle and square. (Extract taken from 'The Secret Plan Of Canberra' by Peter Proudfoot)
