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Roman technology is the engineering practice which supported Roman civilization and made the expansion of Roman commerce and Roman military possible for almost three quarters of a millennium (753 BC–476 AD). The Roman Empire had one of the most advanced set of technologies of its time, some of which was lost during the turbulent eras of Late Antiquity and the early Middle Ages. Gradually, some of the technological feats of the Romans were rediscovered and/or improved upon, while others went ahead of what the Romans had done during the Middle Ages and the beginning of the Modern Era. Several Roman technological feats in different areas like civil engineering, construction materials, transport technology, and some inventions such as the mechanical reaper, were surprising achievements until the 19th century. The Romans achieved high levels of technology in large part because they borrowed and absorbed the culture of the pre-existing (Hellenic and others) peoples of the Mediterranean basin. == The energy constraint == All technology uses energy to transform the material into a desirable object or uses some form of mechanics combined with another form to make something better. The cheaper energy is, the wider the class of technologies that are considered economic. This is why technological history can be seen as a succession of ages defined by energy type i.e. human, animal, water, peat, coal, and oil.〔For a discussion on the importance of energy sources as a constraint on all pre-industrial economies see E.A.Wrigley 2002 'The Quest for the Industrial Revolution' ''Proceedings of the British Academy 121 , 147–170'' available free online, enter '2002 lecture' in search at ()/〕 The Romans used water power, and watermills were common throughout the Empire, especially to the end of the 1st century AD. They were used for cereals milling, sawing timber and crushing ore. They exploited wood and coal for heating. There were huge reserves of wood, peat and coal in the Roman Empire, but they were all in the wrong place. Wood could be floated down rivers to the major urban centres but otherwise it was a very poor fuel, being heavy for its caloric value. If this was improved by being processed into charcoal, it was bulky. Nor was wood ever available in any concentration. Diocletian's Price Edict can give us a glimpse of the economics of transporting wood. The maximum price of a wagon load of 1,200 lbs of wood was 150 d.(denari). The maximum freight charge per mile for the same wagon load was 20 d. per mile. Room heating was normally better done by charcoal braziers than hypocausts. But hypocausts did allow them to exploit any poor-quality smoky fuels like straw, vine prunings and small wood locally available. Hypocausts also allowed them to generate a humid heat for their baths. The Romans worked almost all the coalfields of England that outcropped on the surface, by the end of the 2nd century (Smith 1997; 323). But there is no evidence that this exploitation was on any scale. After c. 200 AD the commercial heart of the Empire was in Africa and the East where the climate severely limited timber growth. There was no large coalfield on the edge of the Mediterranean. Nevertheless, in Roman Egypt all the essential components of the much later steam engine were first assembled by the Greek Mathematician and Engineer Hero: However, the aeolipile was a reaction engine, inefficient as a stationary engine. The first useful steam engine did not use steam pressure at all, but followed up a scientific advance in understanding air pressure. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Roman technology」の詳細全文を読む スポンサード リンク
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