thunder, storm and hail. Further layers of Christian imagery as perceived by the Romantic generation made summit crosses a motif favoured by the painter Caspar David Friedrich in more than one of his mystic landscapes. During the 19th century the summits of many mountains were adorned with what were usually simple, wooden crosses during the course of mountaineering expeditions or survey work, both of which were on the increase. Large summit crosses in the modern sense — that is pieces designed specifically for mountain tops by expert craftsmen — were not really introduced until the end of the 19th century. One known exception is that of the Kleinglockner and Grossglockner, which were given large summit crosses in 1799 and 1800 as part of their first ascent. These crosses, in addition to their religious function, were also used, for example, as lightning conductors, and fitted with meteorological instruments such as barometers. During the 19th century there were several attempts to erect secular symbols such as pyramids, obelisks or flags instead of crosses, usually dedicated to secular rulers. One example was the construction of the so-called Emperor Obelisk on the Ortler in 1888. The 20th century introduced modern materials and technology: a summit cross erected in 1977 on Carrauntoohil, the highest summit in Ireland, originally featured a windmill that powered light bulbs on the cross. What summit crosses may express can be exemplified by the crosses erected and re-erected on the comparatively insignificant Butte de Warlencourt, a pre-Christian tumulus on the Somme, only some 20m above the surrounding terrain but a scene of intense fighting during World War I, when it was the objective of costly and fruitless British attacks during the battle of the Somme: "this pagan memorial was Christianized by bombardment and large numbers of dead," and claimed with first a British cross (1917), then a German one (1918), the latter being removed during the interwar period and replaced by soldiers of the Wehrmacht, in "a symbolic conflict of ownership fought with cruciform images." The erection of summit crosses experienced a boom in the early 20th century. After the First World War and even after the Second World War, many new crosses were erected. Communities often organized this sometimes very expensive and logistically difficult task on very high mountain peaks in the memory of the fallen, and war veterans in particular were often involved in their installation. A superlative example