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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 was used regularly and systematically by early modern humans to heat treat silcrete stone to increase its flake-ability for the purpose of toolmaking approximately 164,000 years ago at the South African site of Pinnacle Point. [11] Evidence of widespread control of fire by anatomically modern humans dates to approximately 125,000 years ago ...
The major confusion involved for many people in this subject is the terminology used. Roman cement was originally the name given, by Parker, to the cement he patented which is a natural cement (i.e. it is a marl, or limestone containing integral clay, dug out of the ground, burnt and ground to a fine powder). [2] [5]
Joseph Aspdin called the product Portland cement because set mortar made from it resembled “the best Portland stone". 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.
Cement powder in a bag, ready to be mixed with aggregates and water. [1] Cement block construction examples from the Multiplex Manufacturing Company of Toledo, Ohio, in 1905. A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together.
The ancient Romans often used olive oil to seal their stone. Such treatment provides some protection by excluding water and other weathering agents, but it stains the stone permanently. During the renaissance Europeans experimented with the use of topical varnishes and sealants made from ingredients such as egg white, natural resins and silica ...
Chesebrough opened his first factory in 1870. The first known reference to the name Vaseline is in his U.S. patent: "I, Robert Chesebrough, have invented a new and useful product from petroleum which I have named 'Vaseline…'" . The word is believed to come from German Wasser (water) + Ancient Greek: έλαιον (élaion, oil). [5]
Oil field in California, 1938. The modern history of petroleum began in the nineteenth century with the refining of paraffin from crude oil. The Scottish chemist James Young in 1847 noticed a natural petroleum seepage in the Riddings colliery at Alfreton, Derbyshire from which he distilled a light thin oil suitable for use as lamp oil, at the same time obtaining a thicker oil suitable for ...