Concise Oxford Dictionary of Archaeology (742 page)

A method for studying the surface and internal structure of a range of materials, including metals, ceramics, and stone, in far more detail than can be achieved with an optical microscope. The transmission electron microscope utilizes a high-energy electron beam generated by a heated filament which is focused onto a specimen by means of a condenser lens. The electron beam illuminates an area just a few microns in diameter. After transmission of the electron beam through the sample an appropriate magnified image of the specimen is formed by the objective lens that throws the image (magnified more than 100000 times) onto a fluorescent screen or photographic plate. The whole process is undertaken under high-vacuum conditions. The sample has to be extremely thin in order to allow the electron beam to pass through it; this is usually achieved by grinding with a fine powder and mounting it on a carbon film. Wear marks on the surface of materials can be examined by making a replica of the surface in plastic or carbon film and examining that under the microscope.

 
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A beam or beams dividing a window horizontally into two or more lights.

 
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Style of flint or stone projectile tip of trapezoidal outline in which the wider straight end forms the leading edge. Typical of the later Mesolithic in northern Europe. Also known as a
PETIT-TRANCHET ARROWHEAD
.

 
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Calcareous bed laid down by water action, especially by springs.

 
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See
TRICHTERBECKER CULTURE
.

 
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An ancient common-law doctrine in the British Isles whereby items of gold and silver (treasure) which are shown to have been hidden with intent to recover, but for which ownership is now unknown, pass to the crown. The finder of such items is, by custom, rewarded with the commercial value of the find. In 1996 the common law was replaced by
The Treasure Act 1996
which came into force in England, Wales, and Northern Ireland on 24 September 1997. This defined treasure as being: any object other than a coin provided that it contains at least 10 per cent of gold or silver and is more than 300 years old; all coins from the same find provided that they are more than 300 years old and contain more than 10 per cent gold or silver, but if less than 10 per cent gold or silver then there must be at least ten of them; associated objects. Such finds must be declared to the local coroner within fourteen days of discovery. Thereafter a lengthy process ensues whereby objects confirmed as treasure are offered to national or local museums, which, if they choose to take the material, must compensate the finder with the value of treasure as determined by an independent valuation panel. Since 1996 the number of items declared treasure has risen significantly.

 
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