In Roman times, drying on a large scale probably relied on sun and wind. One method of drying fish, which was used by the ancients, was to cut them in half and suspend them on ropes to dry in the sun. Often, however, drying was combined with salting to preserve foods. In Mexican and American cuisine drying is still used to preserve beef and to change the flavor of the meat.
Salting
The use of salt was an important and well-documented means of preservation for the Romans. The Romans produced some salt by evaporating seawater in earthenware vessels, and their supply was supplemented by salt produced at the brine springs of Droitwich, and a place in Cheshire. These places were known as salinae, or "salt flats." Salt was used for the preservation of green olives in brine. Today salting is a method of cuisine rather than conservation.
Concrete
In the actual days there is no foundation that does not have concrete. Concrete is essential to any building in the United States. Tons and tons are used for any kind of construction, from roads to the highest skyscraper. The Greeks made lime mortar, and special hydraulic cements and plasters. The Romans discovered that adding to the lime mortar produced a concrete that would be much stronger. The magic ingredient in Roman concrete is pozzolana (Portland cement), a powdered volcanic ash. It contains silica, aluminum & iron oxide. Make lime mortar as usual, but add pozzolana to the mix as the powder; the result will set under water, and (unlike traditional mortar) was stronger than the stones joined by it. The Romans called it caementum, whence cement. Concrete was used as a filling grout for roads and mortar to join stone and other materials for construction. Concrete building is very rough looking, so it was covered by other materials such as: brick, mosaic, marble. As they do today.
The Arch
Some of the Roman’s most famous architectural discoveries were the arch. The arch let them build temples, other buildings and bridges so that they were much stronger, and could support much more weight so the buildings could be much bigger. It was also much more durable than the post and lintel technique, so the buildings made of arches would last for a much longer time. The arch is a very important discovery by the Romans because a bridge can be extended much farther than a lintel bridge and that discovery was a revolution in architecture that allowed the new architects to build the bridges that we have today and the domes of the modern buildings.
Roads
In typical Roman road construction, a mosaic of heavy paving blocks closely trimmed and fitted is laid over a bedding of gravel and sand. This type of construction is the most used today. ranging from the brick pavers to the fastest highway in the U.S.A. for a common paved way The foundation is gravel, then concrete is poured, and finally the black top which is asphalt. But the basis of the modern road construction is pretty much the same technique that the Romans used.
Heated Swimming pools
The first civilizations to build swimming pools were the Egyptians, but the first civilization to build the heated swimming pools were the Romans. And Gaius Maecenas, rich roman who loved art and supported famous poets, built it. Today a heated swimming pool is something that only a person with enough economic solvencies can afford (do not have to be a roman necessarily). The most important use of the heated swimming pool is at the Olympic games
http://www.bbc.co.uk/schools/romans/tech.shtml
