Technology, Function, and Human Activity

A series of case studies are used to illustrate the study of technology, function, and past human activity. These studies include a variety of microscopic and instrumental methods to look at a number of different kinds of material. The discovery of the early use of fire has involved both archaeological chemistry and distribution studies of specific artifact types to try and document that humans used and controlled fire more than 500,000 years ago. 

In archaeological chemistry, the study of technology takes several directions. The investigation of technology itself, how things were created or manufactured, is an important area. Information on the materials that were used, the temperatures, conditions, and methods of production can tell us about the capabilities of society and the evolution of technology. 

Ceramics provide a good example of the application of archaeological chemistry to the study of technology. In its simplest fonn, pottery is made of clay. The type of clay used determines the quality of the ceramic that is produced. Types of clay can be identified using techniques like X-ray diffraction described in Chap. 6, Instruments. Temper is often mixed with raw clay to produce an improved material for firing. The material used for temper (sand, fine gravel, shell, bone, or other materials) can be identified using a binocular microscope. 

Typical prehistoric pottery, called earthenware, requires temperatures between 900 and l,200°C (l,650-2,200°F) to vitrify. Fine porcelain pottery made from kaolin clay is fired at l,280-l,350°C (2,300-2,400°F) it is white and often translucent. A modem kitchen stove will produce temperatures ca. 260°C (500°F). An open wood fire produces temperatures in the range of 800-900°C (l,450-l,650°F). Closed kilns, a kind of oven, can reach temperatures of l,000°C (l,830°F) or more. Table 6.1 provides some information on firing temperatures, kiln conditions, and the type of ceramic produced. The conditions of firing determine the color of the pottery that is produced. 

Pottery in a closed kiln is fired in a reducing atmosphere, lacking oxygen. Vessels fired in an open-air hearth are oxidized. Oxidizing atmospheres produce pottery with dark, black cores, while reducing atmospheres produce ceramics with lighter, reddish interiors. 

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Rehabilitation of humans with sensory-motor disability requires effective assistive systems that would allow their fast and maximal reintegration into the normal fife. The cost-benefit functions that humans with disability likely appreciate and optimize comprise elements, such as (1) the quality of life measured by reintegration into the social and work environments (2) reliability of the assistive system (3) energy rate and cost with respect to the one used for accompHshing the same task with alternative methods (4) disruption of normal activities when employing the assistive system (5) cosmetics (6) maintenance and (7) cost. The same elements are considered, but, in a different order by the developers of the rehabilitation technology, practitioners of physical medicine, and rehabilitation and health-care providers. 

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