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A dugout canoe or simply dugout is a boat made from a hollowed tree trunk. Other names for this type of boat are logboat and monoxylon. ''Monoxylon'' (''μονόξυλον'') (pl: ''monoxyla'') is Greek -- ''mono-'' (single) + ''ξύλον xylon'' (tree) -- and is mostly used in classic Greek texts. In Germany they are called einbaum ("one tree" in English). Some, but not all, pirogues are also constructed in this manner. Dugouts are the oldest boats archaeologists have found, dating back about 8,000 years to the Neolithic Stone Age.〔1000 Inventions and Discoveries, by Roger Bridgman〕 This is probably because they are made of massive pieces of wood, which tend to preserve better than, e.g., bark canoes. Along with bark canoe and hide kayak, dugout boats were also used by indigenous peoples of the Americas. ==Construction== Construction of a dugout begins with the selection of a log of suitable dimensions. Sufficient wood needed to be removed to make the vessel relatively light in weight and buoyant, yet still strong enough to support the crew and cargo. Specific types of wood were often preferred based on their strength, durability, and density. The shape of the boat is then fashioned to minimize drag, with sharp ends at the bow and stern. First the bark is removed from the exterior. Before the appearance of metal tools, dugouts were hollowed-out using controlled fires. The burnt wood was then removed using an adze. Another method using tools is to chop out parallel notches across the interior span of the wood, then split out and remove the wood from between the notches. Once hollowed out, the interior was dressed and smoothed out with a knife or adze. More primitive designs keep the tree's original dimensions, with a round bottom. However, it is possible to carefully steam the sides of the hollow log until they are pliable, then bend to create a more flat-bottomed "boat" shape with a wider beam in the centre. For travel in the rougher waters of the ocean, dugouts can be fitted with outriggers. One or two smaller logs are mounted parallel to the main hull by long poles. In the case of two outriggers, one is mounted on either side of the hull. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dugout canoe」の詳細全文を読む スポンサード リンク
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