Tarmac
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Tarmac, short for tar-penetration macadam, is a type of highway pavement no longer commonly used. Tarmac was invented when E. Purnell Hooley was passing a tarworks in 1901.
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Origins
Macadamized roads were adequate for use by horses and carriages or coaches, but they were very dusty and did not hold up to higher speed motor vehicle use. Passing a tarworks in 1901, Hooley observed a a barrel of tar had spilled on the roadway, and in an attempt to reduce the mess, gravel had been dumped on top of it. The area was remarkably dust-free compared to the surrounding road.
Commerical activities
This observation inspired Hooley to develop and patent Tarmac in Britain (and, later, in America). He called his company Tar Macadam (Purnell Hooley's Patent) Syndicate Limited, but unfortunately he had trouble selling his product as he was not a very competent businessman. His company was soon bought out by the Wolverhampton MP, Sir Alfred Hickman, the owner of a steelworks which produced large quantities of waste slag. The Tarmac company was relaunched in 1905, and became an immediate success (Tarmac plc remains a major player in the UK market for heavy building materials, having divested itself of its housing and contracting interests during the 1990s).
Later developments
As petroleum production increased, the byproduct asphalt became available in huge quantities and largely supplanted tar due to its reduced temperature sensitivity. The Macadam construction process also became quickly obsolete due to its high manual labour requirement. While the specific Tarmac pavement is not common today, many paved surfaces are generically referred to as "tarmac." Many people use the word to refer to paved areas at airports, especially regions near the terminals. The airport at Wick in Caithness, Scotland is one of the few airports that still has a real tarmac runway.
Patents
- Hooley, E. Purnell, Template:US patent, "Apparatus for the preperation of tar macadam", July 26, 1904.