can be scraped with a knife to make a powdered tinder that will burn for a few seconds. Hiking stores sell both magnesium starters, firelighter blocks, and other specialist tinder. Lighters Lighters typically use a percussion-type sparking device to ignite gas/liquid fuels such as butane or naphtha/gasoline. These are simple to light, often using a wheel mechanism that when spun with the thumb creates friction on the internal rod of ferrocerium "flint" and throws a shower of white-hot sparks into the gas or wick. Alternately, an electric spark ignites the fuel. With almost 2 billion lighters sold each year, this is the most popular means to light fires today. Compression of air A fire piston ignites a combustible substance that holds an ember (e.g. charcloth) by rapid compression of air. Similar to how a Diesel engine works, rapid compression of air heats the interior to 400–700 °F, well above the tinder's autoignition temperature. Solar Sunlight can be concentrated using a lens (such as a burning glass) to focus the energy from the sun onto tinder. A concave mirror can also concentrate the sun's rays onto tinder. Chemical An exothermic chemical reaction can generate enough heat as to catch itself or tinder on fire. Matches are small sticks of wood or stiff paper with a coating that undergoes an exothermic reaction when triggered by friction. Other reactions that can be used to start fires include: calcium hypochlorite and automotive brake fluid potassium permanganate and glycerin potassium permanganate, acetone, and sulfuric acid sodium chlorate, sugar, and sulfuric acid ammonium nitrate powder, finely ground zinc powder, and hydrochloric acid sulfuric acid, zinc, and platinum (as in Döbereiner's lamp) Percussion caps, as used in muzzleloader firearms, and primers used in rifle and shotgun shells create a stream of sparks when rapidly struck. Electrical Electrical firemaking involves the contact of an electrically heated object to tinder. A current is run through the object until it is red hot, like the burners on an electric stove, and it is brought into contact with the tinder, lighting it. For example, a foil-paper chewing gum wrapper will heat-up and ignite; or a flashlight battery coming into contact with a thin wire mesh (such as steel wool) may produce enough heat to ignite charcloth or other tinder. Larger batteries can generate sparks when its leads touch. See also Bushcraft Firestarter (disambiguation) Glossary of firelighting Quest for Fire (film) Survival