Climbers around the world use different techniques to accomplish great feats of ascent and descent. One technique for descending in precarious circumstances, abseiling, is a way to control the descent using special tools and protection. The term 'abseiling' is derived from the German word 'abseilen', which means 'to rope down'. The term used for the technique varies from country to country, including slang terms such as rap jumping (America), snapling (Israel), seiling (Australia), abbing (Britain), and rappling (Hindi). The origin of the abseil technique is attributed to Jean Esteril Charlet, a mountaineering guide who originally devised the method of roping down during a failed attempt to climb Petit Dru alone in 1876. After many failed attempts, he managed to reach the summit in 1879, along with two other Chamonix guides whom he had hired to accompany him. During that ascent, Charlet perfected the technique of abseiling. There are various methods of abseiling and an assortment of various tools climbers can use. A very important piece of safety equipment is a helmet, with or without a light source mounted on it, to protect the head from falling rocks. Gloves are used by recreational abseilers, adventure racers, and military climbers to protect the hands from the climbing ropes. The ropes used for abseiling are typically made of a multi-strand core protected by a woven sheath. A comfortable but snug harness is used around the waist to secure the climber. Boots or sturdy footwear are required to maintain sure footing on uneven or wet surfaces. Abseiling is used by numerous people for a wide variety of reasons. Recreational canyon hikers travel down mountainous water systems where waterfalls may need to be descended and climbing or jumping is too dangerous. Rock climbers use abseiling techniques to return to the base they ascended from, or to lower themselves to a point where they can try a new route. Industrial or commercial workers such as quarry workers and window washers use abseiling techniques to gain access to parts of buildings to perform repairs, construction, or cleaning. Rescue workers and paramedics often do it to access injured people or confined spaces by rapelling from a hovering helicopter or a location above an accident site. Military special forces and police SWAT teams enter tall buildings through windows, or reach confined spaces via aircraft. One tool specific to abseiling is a descender or rappel device. This tool is a friction hitch that allows for a rope to be played out in a controlled fashion with minimal effort. The speed of descent is controlled by the climber, who applies greater or lesser force on the rope below the descender, or by altering the angle at which the rope emerges from the descender. There are various versions of mechanical descenders, such as braking bars, the abseil rack, the gold tail, and the 'sky genie' used by wildfire fighters or window washers. Abseiling can be a risky and dangerous sport, especially for inexperienced or solo climbers. Most climbers view abseiling as more dangerous than merely climbing, because the rope system is carrying the weight of the climber all the time, rather than only in the event of a fall. A high percentage of injuries and deaths attributed to 'climbing accidents' are actually the result of mistakes made while abseiling. As a result, descent by abseiling is discouraged in many areas and prohibited in many public areas, because of potential conflict with climbers who are ascending.