Eastwoodhill Arboretum

The Fibonacci Spiral

Eastwoodhill’s Fibonacci Spiral.

Constructed in 2009 as a memorial to Mr H.B Williams (Bill), who purchased Eastwoodhill from Douglas Cook in 1965 with the sole intention to ‘preserve it for the future and for the enjoyment of all interested in horticulture.’ Bill established the Eastwoodhill Arboretum Trust in 1975, which effectively gifted the Arboretum to New Zealand, securing it’s future. Financial contributions from Bill and other Williams family trusts established the Eastwoodhill Endowment fund, which allows continued management and development of the park. Bill died in 2002, having secured Eastwoodhill’s future and fulfilling the dream of Douglas Cook.

The Spiral.

Eastwoodhill’s Fibonacci Spiral is an example of the ancient mathematical theory. The squares which relate to Fibonacci numbers are visible at ground level and are what the spiral intersects as it expands from the centre. Follow the spiral as it expands from it’s central point out into the Arboretum.

After extensive planning by the Williams family and designed by Landscape Architect Sue Dick, construction of the Fibonacci Spiral began in March 2009, and was completed in November 2009. Stonemason Aaron Boyle used Basaltic Andersite, a volcanic rock from Rainbow Mountain near Rotorua, for the central part of the spiral, shaping the rock by hand. As the spiral expands, the rock used changes to Limestone rock which is known for its preservation of fossils. The wall of Limestone was constructed using a ‘drystack’ method, a European style of construction using no Mortar.

At the centre of the spiral is a Granite ball feature. This solid 750kg ball, imported from China is suspended by water in a system which involves only 15psi water pressure. This suspension eliminates friction and allows the ball to be rotated and spun with very little effort.