piece. Although hooks are often categorized as clean, they easily damage soft rock and can even damage granite. History Morley Wood during the ascent of Pigott's Climb on Clogwyn Du'r Arddu (North Wales) in 1926 reportedly was the first climber to use pebbles slung with rope for protecting a rock climb. These were replaced by the use of machine nuts in England during the 1950s. In 1961, John Brailsford of Sheffield, England, reportedly was the first to manufacture nuts specifically for climbing. Rock scarring caused by pitons was an important impetus for the emergence of the term, and the initial reason climbers largely abandoned pitons. However, today what was in the 1970s called "clean protection" and regarded by many climbers of the day with some suspicion with regard to safety, is now recognized as a faster, easier, more efficient and safer means of protecting most climbing routes than pitons- which are now, in comparison with the 1960s, rarely used. When chrome molybdenum steel pitons replaced softer iron in the early 1960s, pitons became more easily removable, resulting in their more intensive use and alarming damage to increasingly popular climbing routes. In response, there was a "movement" among U.S. climbers around 1970 to eliminate their use. Although bolts continue to be used today for sport climbing, and aid climbers, rescuers and occasionally mountaineers may employ pitons, bolts and a variety of other hammered techniques, the average free climber today has no experience with hammering or drilling. Prior to the introduction of spring-loaded camming devices (in about 1980), clean climbing involved a safety trade-off in certain situations. Protection methods of today, however, are generally seen as faster, safer and easier than those of the piton era, and average run-outs between gear placements have probably become shorter on many routes. Although English climbers had long used stones wedged into cracks and slung with cord for protection, this practice was rare in the U.S. In the early 1960s, after climbing a while in Britain, Yale physicist and notable New England climber, John Reppy, imported nylon-slung machine nut protection to Connecticut's Ragged Mountain. Soft-steel pitons held poorly in Ragged Mountain's cracks, and the nuts provided a more reliable protection. Nuts were therefore used as climbing protection in Connecticut about a decade before popular use in the U.S. In 1967, Royal Robbins returned from England with a sampling of artificially manufactured chock stones. He promptly made