Teacher background information

This elaboration provides students with the opportunity to learn that Aboriginal and Torres Strait Islander Peoples have for millennia selected and used natural and processed materials for many purposes, based on the physical properties of the material. Aboriginal and Torres Strait Islander Peoples understand the physical properties of natural materials and have procured and utilised materials from the environment to construct tools, manufacture clothing and construct shelters. Furthermore, Aboriginal and Torres Strait Islander Peoples understand how natural materials can be processed in particular ways. Such processes modify the physical properties of natural materials and enable them to be used for particular purposes that could not occur in their natural form. Students will have the opportunity to learn how Aboriginal and Torres Strait Islander Peoples’ longstanding scientific knowledge of the physical properties of materials has informed, and continues to inform, the selection of natural and processed materials for specific functions. 

Prior to European arrival in Australia, there were more than 500 distinct Aboriginal and Torres Strait Islander Nations, each occupying a specific geographical territory. The region occupied by an Aboriginal or Torres Strait Islander People determined the resources that were available; these resources were sustainably harvested to provide medicines, tools, shelter, clothing, food and weapons. In the development of material culture, Aboriginal and Torres Strait Islander Peoples understood the physical properties of the natural materials available in their Country/Place, such as hardness, flexibility, absorbency, strength, buoyancy, permeability, malleability and elasticity. The physical properties of materials required for different aspects of daily life, such as the construction of shelters or manufacture of tools and clothing, varied greatly and required resources with suitable physical properties. These materials may have been processed prior to use, to improve specific physical properties of the material, thus making it more suited to its function. Aboriginal and Torres Strait Islander communities throughout Australia utilise their material science knowledge and understanding in the continuation of cultural practices.

Plant materials have long been used by Aboriginal and Torres Strait Islander Peoples in the construction of tools, weapons and shelters. Many parts of a plant can be used, including the wood, bark, roots and leaves. Knowledge of the natural properties of the various species of plants in a given geographical region informs the selection of materials for specific purposes, such as in the construction of domestic implements and weapons. For example, dense woods are used to construct implements for striking and digging that need to be hard, heavy and durable, whereas implements such as boomerangs are constructed from material that is strong but not heavy. The manufacture of different types of spears demonstrates Aboriginal and Torres Strait Islander Peoples’ understanding of the physical properties of natural materials and illustrates the careful and purposeful selection of a material based on the desired purpose. The construction of fishing spears requires the selection of a natural material that is lightweight, buoyant and flexible, so that the spear will float to the water surface to be retrieved after use. The Meriam Peoples of the eastern Torres Strait Islands use lightweight bamboo to construct baur (multi-pronged fishing spears). The Gumbaynggirr Peoples of the mid north-west coast of New South Wales construct biguurr (fishing spears) from lightweight woods native to the area, such as cottonwood, hibiscus and grass tree. Spears used for hunting large game, such as emu and kangaroo, require wood of a higher density to maximise the impact on the target. In the past, the Paredarerme people of the Oyster Bay region of Tasmania constructed perenna (hunting spears) from tea tree or Eucalyptus spp., materials that are light and durable. In the Musgrave Ranges region of the Western Desert, the Yankunytjatjara Peoples construct oiritchanna (composite hunting spears) from different woods that are selected for their natural properties. A light flexible wood obtained from plants such as the wonga wonga vine is used for the spear shaft, and a hard, heavy material such as mulga is used to construct the spear head. The combination of materials achieves the optimal physical properties for a hunting spear - strength, flexibility and durability.

Aboriginal and Torres Strait Islander Peoples apply processes to wood and bark, such as steaming, to alter the physical properties of the material. Steam bending is a technique whereby heat and moisture are applied to wood or bark to modify its physical properties. Wood and bark, when they are separated from the tree and dried, become rigid, difficult to bend and break easily. Steaming adds moisture and heat to wood and bark and results in plasticisation of the material. This treatment process confers the physical properties of improved malleability, the ability to mould the material into a desired form, and a reduced tendency to break. Steam bending has long been used, and continues to be used, by Aboriginal and Torres Strait Islander Peoples to treat wood and bark for a variety of applications.

Prior to European colonisation, the Punnilerpanner Peoples of the Port Sorell area in northern Tasmania constructed unique beehive-shaped shelters. The dome-shaped shelter was constructed using wooden structural supports that had been steamed by fire to facilitate bending. Heat can be applied to moist sections of freshly harvested bark. The heat generates steam within the bark and allows the curled section of bark to be flattened into sheets for the construction of shelters and as a canvas for painting. The Wodiwodi Peoples of the Illawarra region on the south coast of New South Wales used flattened sheets of warreeah (a Dharawal word that translates to stringybark in English) to cover the frame of a shelter. The Yolŋu Peoples at Yirrkala in east Arnhem Land in the Northern Territory use stringybark as a canvas. The bark is cut from the tree during the wet season to take advantage of the ambient moisture which facilitates its removal. It is then heated over a fire to alter the physical properties of the bark, making it flexible and malleable so that it can be flattened. Yolngu Peoples have utilised this scientific knowledge for millennia in the production of bark canvases, including in the production of the 1963 Yirrkala bark petitions, and continue to use this knowledge today.

Steam processing of bark is also used in the construction of water vessels. The Gunaikurnai Peoples of the Gippsland region of Victoria steamed sheets of stringybark over a fire to improve pliability for the construction of canoes. Once steamed, the bark could then be shaped by turning up the sides and folding the edges together to construct a watertight vessel with the capacity to carry multiple passengers.

Other plant parts are used to manufacture domestic implements and are selected based on their physical properties. Many raw, unprocessed fibres are lightweight, strong and flexible, making them ideal for use as string. Aboriginal and Torres Strait Islander Peoples use fibres in their natural state for tying materials and objects together and in the manufacture of clothing. The Yir Yoront Peoples of the Kowanyama region of Cape York Peninsula use lengths of the strong, flexible lawyer cane stem to tie roofing material onto shelters. The Koeybuway and Moegibuway Peoples of Saibai Island in the Torres Strait have long-used lawyer cane for its tough, pliable physical properties; split into strips it is used in the construction of houses. Natural fibres were also used prior to colonisation in the manufacture of clothing. For example, lawyer cane was used to stitch together clothing, such as dresses made from bark, and on the north-west coast of Western Australia, the Nyangumarta Peoples manufactured sandals from the unprocessed creepers of the dodder vine.

Aboriginal and Torres Strait Islander Peoples also process fibre to improve its strength and durability. Processed string and cord are used to manufacture nets, baskets, bags, belts and mats for fishing and to catch game, and for other woven or netted items. The Gunai Peoples of the Gippsland region in Victoria have long processed kangaroo grass to manufacture string for nets. The collected grass is steamed to soften the natural fibre and allowed to cool. The pulp is removed through chewing and the fibre is then washed and dried. Twine is then made by twisting and winding two strands of the processed fibre together. The Mabuaig Peoples of Mabuaig Island in the Torres Strait process coconut husk to manufacture string. The husks are soaked for up to two weeks in water until soft and then they are pounded. Individual fibres are separated and scraped to remove pulp or broken remnants, dried in the sun, and then twisted together into strands. The processed material is strong and durable and is used to manufacture fishing lines. The Mabuaig Peoples understand the physical properties and limitations of the string, and they twine up to four strands together to increase the tensile strength of the string, to use when fishing for large marine animals.

Additional processing may be incorporated in the manufacture of string to confer specific physical properties. The Dharawal Peoples of the Beecroft Peninsula region on the southern New South Wales coast tan fishing lines with plant gum to prevent fraying and to increase durability. The Yidinji Peoples of far north Queensland use wax from native bees to make string waterproof and more resistant to weathering. In parts of Australia, oil such as emu oil is rubbed into the fibre while it is being twined, to impart suppleness and flexibility to the cord. 

Rock is a natural material that has long been used by Aboriginal and Torres Strait Islander Peoples in the construction of stone tools. Knowledge of the properties of different types of rock informed the selection of specific rock types for particular purposes. Aboriginal and Torres Strait Islander Peoples have used grindstones for millennia to process seeds, carefully selecting the appropriate rock type based on its physical properties. Sandstone has long been widely used as a grindstone across Australia as it has a rough surface to efficiently process seeds. However, Aboriginal Peoples also understand that another physical property of sandstone is that it is porous and has a higher absorbency rate than other rock types. The Jirrbal Peoples of the Atherton Tableland region in far north Queensland do not use sandstone grindstones for processing the toxic cycad nut, as the process may deposit toxic residue in the stone. In this region, cycad seeds are processed using slate grinding stones. The physical properties of slate, a metamorphic rock, include low porosity and thereby low absorbency and potentially reduced retention of dangerous toxins.

Aboriginal and Torres Strait Islander Peoples use their understanding of the properties of stone to carefully select stone that allows processing to confer particular physical properties, such as sharpness. Metamorphic rocks such as quartzite and chert have the physical properties of being fine grained, uniform in texture, hard and dense. They fracture in a predictable pattern on impact, known as a Hertzian (conchoidal) fracture, that results in a sharp edge. The Nyikina Peoples and the Karadjeri Peoples of the Kimberley region of Western Australia used local quartzite to manufacture stone tools with unique bifacial points known as Kimberley Points. These items maintain enduring importance as spearheads and surgical tools. The points are produced by percussion flaking to partly form the desired shape. Then the delicate, serrated edges are honed using a bone tool for careful, controlled pressure flaking at specific points along the edge of the stone. In parts of Australia, raw quarried stone blanks were also pre-processed, using heat to improve flaking quality.

Aboriginal and Torres Strait Islander Peoples understand the physical properties of natural materials that are used to manufacture clothing. Prior to colonisation, clothing was manufactured to suit the environmental conditions, and varied greatly across the Australian continent. Aboriginal Peoples whose Country encompasses cool, wet climates manufactured clothing from the furs of a variety of animals, including wallabies, kangaroo, possum, platypus and quoll. The physical properties of the fur of these animals provided thermal insulation and impermeability to water. In wet weather, the Wiradjuri Peoples of central New South Wales wore animal furs with the fur side to the rain as this orientation protected the wearer from water, whereas the skin side became saturated when exposed to the rain. In cool, dry weather the Gunditjmara Peoples of western Victoria wore possum furs with the fur side inwards, providing thermal insulation through trapping of warm air between the fibres. Similarly, the Noongar Peoples of south-west Western Australia manufactured buka (kangaroo skin cloaks) from the hide of kangaroos, also worn with the fur facing inwards for warmth.

Tanning is the chemical process of treating skins and hides of animals to produce leather employed by many First Nations Peoples of the world. Aboriginal Peoples use the tanning process to alter the physical properties of animal skins to make them more durable and to prevent decomposition. The Wodiwodi Peoples of the Illawarra region on the south coast of New South Wales use the sap from Myimbarr (a Dharawal word that translates to two-veined hickory, a species of Acacia, in English) to tan the hides of animals. Water carriers, essential for storing and carrying water over long distances, can hold up to 19 litres of water. The capacity of the water carrier depends on the size and type of mammal hide used, including kangaroo, possum, wallaby and bandicoot. Tanning, to preserve the material and ensure the waterproof nature of the container, is carried out using resinous materials from a variety of plants, including Eremophila spp. and Acacia spp. The Wiradjuri Peoples of central New South Wales tanned the hide of wallabies to manufacture water carriers. The wallaby skin was removed in one piece, taking care not to pierce or puncture the skin. The hide was then dried and tanned with resin to improve durability and ensure that it was waterproof. In Queensland, kangaroo skin water carriers were tanned with bloodwood gum. These specialised hydration backpacks are called nilpa by the Pitta Pitta Peoples and norlo by the Kalkadoon Peoples of far western Queensland.

This elaboration provides students with the opportunity to learn that Aboriginal and Torres Strait Islander Peoples have longstanding scientific knowledge and understanding of the physical properties of natural and processed materials. The properties of natural materials influenced, and continue to influence, their use in a range of contexts, including in the construction of shelters, manufacture of clothing and production of tools. Furthermore, Aboriginal and Torres Strait Islander Peoples understand the processes that can be applied to modify the physical properties of natural materials to fulfil a particular purpose. Students can learn how Aboriginal and Torres Strait Islander Peoples have long understood and applied knowledge of the physical properties of natural and processed materials to many applications.