from yew, ash or elm. The draw force of a 10th-century bow may have reached some 90 pounds force (400 N) or more, resulting in an effective range of at least depending on the weight of the arrow. A yew bow found at Viking Hedeby, which probably was a full-fledged war bow, had a draw force of well over 100 pounds. Replica bows using the original dimensions have been measured to between draw weight. A unit of length used in the Viking Age called a bow shot corresponded to what was later measured as . Illustrations from the time show bows being pulled back to the chest, rather than to the corner of the mouth or under the chin, as is common today. Arrowheads were typically made from iron and produced in various shapes and dimensions, according to place of origin. Most arrowheads were fixed onto the arrow shaft by a shouldered tang that was fitted into the end of a shaft of wood. Some heads were also made of wood, bone or antler. Evidence for eagle feather flights has been found with the feathers being bound and glued on. The end of the shaft was flared with shallow self nocks, although some arrows possessed bronze cast nocks. The historical record also indicates that Vikings may have used barbed arrows, but the archaeological evidence for such technology is limited. The earliest find of these relics were found in Denmark, seemingly belonging to the leading-warrior class based on the graves in which they were found. Shields Round shields The shield was the most common means of defence. The sagas specifically mention linden wood for shield construction, although finds from graves show mostly other timbers, such as fir, alder and poplar with steel or iron shield boss. These timbers are not very dense and are light in the hand. They are also not inclined to split, unlike oak. Also, the fibres of the timber bind around blades preventing the blade from cutting any deeper unless a lot more pressure is applied. In conjunction with stronger wood, Vikings often reinforced their shields with leather or, occasionally, iron around the rim. Round shields seem to have varied in size from around in diameter but is by far the most common. The smaller shield sizes came from the pagan period for the Saxons and the larger sizes from the 10th and 11th centuries. Most shields