the Jumar for him. The first iteration of the tool was sold in 1958. The device's name also engendered the verb "to jumar" for the process of using such a device. In jumaring, the second climber (the one who belays the lead climber on the route) uses ascenders to climb the rope instead of climbing directly on the rock. Other terms for this process include ascending and jugging. This process is similar to prusiking, except using an ascender device instead of friction knots. In his memoir Life Is Meeting, John Hunt, leader of the 1953 British Mount Everest expedition, credits the jumar with enabling climbers "to climb at alpine standards even at high altitudes". Non-mechanical devices In place of mechanical ascenders, one or more thin rope slings (or prusik loops) may be used which can be slid along the thicker climbing rope when not under tension. These friction knots will lock under load to enable the climber to use the strength of their leg to step up and ascend the rope. Prusik knots are much lighter, but are not capable of taking a dynamic load, such as arresting a falling climber, because they are prone to melting or fusing under such extreme forces. Single-rope technique In caving, ascending a rope by means of mechanical devices is often necessary and is the main alternative to ladder use. This is termed single-rope technique. The rock which forms the cave is often wet, slippery, relatively featureless and often unreachable from the necessary rope locations. So climbing the rope may well be preferable to climbing the rock or a ladder, provided that a belay location that provides an ascent has already been found. Although climbers may regard a climb as a challenge to be tackled with minimal aids, cavers are likely to consider it as an obstacle to their progress to be overcome as conveniently as possible, and are more inclined to make use of mechanical ascenders. History The first mechanical rope ascending devices were created by Henri Brenot, and were used in France both for mountaineering and caving as early as 1934. Jümar Pangit, a Swiss manufacturer located then in Reichenbach (Switzerland), was founded by Adolph Jüsi and Walter Marti. Jüsi was studying eagles for the Swiss government and needed to ascend on ropes in order to perform his work, so Marti developed the ascender for him. In 1958, the first jumar was