second story galleries of large stone churches elsewhere in Europe. Smaller beams running between these upper supporting columns help clamp everything firmly together. The weight of the roof is thus supported by buttresses and columns, preventing downward and outward movement of the stave walls. The roof beams are supported by steeply angled scissor trusses that form an "X" shape with a narrow top span and a broader bottom span, tied by a bottom truss to prevent collapse. Additional support is given by a truss that cuts across the "X", below the crossing point but above the bottom truss. The roof is steeply pitched, boarded horizontally and clad with shingles. The original outer roof would have been weatherproofed with boards laid lengthwise, rather than shingles. In later years wooden shingles became more common. Scissor beam roof construction is typical of most stave churches. Dragons Borgund has tiered, overhanging roofs, topped at their intersection by a shingle-roofed tower or steeple that straddles the ridge. On each of its four gables is a stylised "dragon" head, swooping from the carved roof ridge crests, Hohler remarks their similarity to the carved dragon heads found on the prows of Norse ships. Similar gable heads appear on small bronze church-shaped reliquaries common in Norway and Europe in this period. Borgund's current dragon heads are possible 18th century replacements; similar, original dragon heads remain on older structures, such as Lom Stave Church and nearby Urnes Stave Church. Borgund is one of the only stave churches to have preserved its crested ridge caps. They are carved with openwork vine and entangled plant designs. The four outer dragon heads are perhaps the most distinctive of all non-Christian symbols adorning Borgund Stave Church. Their function is uncertain, and disputed; if pagan, they are recruited to the Christian cause in the battle between Good and Evil. They may have been intended to keep away evil spirits thought to threaten the church building; to ward off evil, rather than represent it, On the lower side panel of the steeple are four carved circular cutouts. The carvings are weather-beaten, tarred and difficult to decipher, and there is disagreement about what they symbolize. Some believe they represent the four evangelists, symbolised by an eagle, an ox, a lion and a man. Hauglid describes the carvings as "dragons that extend their heads over to the neighboring field's dragon and bite into it", and points out