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A fire ring is a construction or device used to contain campfires and prevent them from spreading and turning into wildfires. [citation needed] A fire ring is designed to contain a fire that is built directly upon the ground, such as a campfire. Fire rings have no bottom, and are simply circles made of forged metal, stones, concrete, etc. which ...
Fire allowed major innovations in tool and weapon manufacture. Evidence dating to roughly 164,000 years ago indicates that early humans in South Africa during the Middle Stone Age used fire to alter the mechanical properties of tool materials applying heat treatment to a fine-grained rock called silcrete. [40]
Portland stone was the most prestigious building stone in use in England at the time. The patent clearly does not describe the product recognised as Portland cement today. The product was aimed at the market for stuccos and architectural pre-cast mouldings, for which a fast-setting, low-strength cement was required (see cement).
The word "cement" can be traced back to the Ancient Roman term opus caementicium, used to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick supplements that were added to the burnt lime, to obtain a hydraulic binder , were later referred to as cementum ...
An example of a temple made of Roman concrete in the 1st century BC is the Temple of Vesta in Tivoli, Italy. The concrete was made of nothing more than rubble and mortar. It was cheap and very easy to produce and required relatively unskilled labour to use, enabling the Romans to build on an unprecedented scale.
Historically, flint was widely used to make stone tools and start fires. Flint occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones. [3] [4] Inside the nodule, flint is usually dark grey or black, green, white, or brown in colour, and has a glassy or waxy appearance. A thin, oxidised layer on the outside of ...
A fire striker is a piece of carbon steel from which sparks are struck by the sharp edge of flint, chert or similar rock. [ 1 ] [ 2 ] [ 3 ] It is a specific tool used in fire making . History
A concretion is a hard and compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. [1] Concretions are often ovoid or spherical in shape, although irregular shapes also occur.