RudderA rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end.
Mongol invasions of JapanMajor military efforts were taken by Kublai Khan of the Yuan dynasty in 1274 and 1281 to conquer the Japanese archipelago after the submission of the Korean kingdom of Goryeo to vassaldom. Ultimately a failure, the invasion attempts are of macro-historical importance because they set a limit on Mongol expansion and rank as nation-defining events in the history of Japan. The invasions are referred to in many works of fiction and are the earliest events for which the word kamikaze (神風 "divine wind") is widely used, originating in reference to the two typhoons faced by the Yuan fleets.
Kangxi EmperorThe Kangxi Emperor (4 May 1654 – 20 December 1722), also known by his temple name Emperor Shengzu of Qing, personal name Xuanye, was the third emperor of the Qing dynasty, and the second Qing emperor to rule over China proper, reigning from 1661 to 1722. The Kangxi Emperor's reign of 61 years makes him the longest-reigning emperor in Chinese history (although his grandson, the Qianlong Emperor, had the longest period of de facto power, ascending as an adult and maintaining effective power until his death) and one of the longest-reigning rulers in history.
BambooBamboos are a diverse group of mostly evergreen perennial flowering plants making up the subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family, in the case of Dendrocalamus sinicus individual culms reaching a length of 46 meters, up to 36 centimeters in thickness and a weight of up to 450 kilograms. The internodes of bamboos can also be of great length. Kinabaluchloa wrayi has internodes up to 2.5 meters in length.
Fra Mauro mapThe Fra Mauro map is a map of the world made around 1450 by the Italian (Venetian) cartographer Fra Mauro, which is “considered the greatest memorial of medieval cartography." It is a circular planisphere drawn on parchment and set in a wooden frame that measures over two by two meters. Including Asia, the Indian Ocean, Africa, Europe, and the Atlantic, it is oriented with south at the top. The map is usually on display in the Biblioteca Nazionale Marciana in Venice in Italy. The Fra Mauro world map is a major cartographical work.
Liaodong PeninsulaThe Liaodong or Liaotung Peninsula () is a peninsula in southern Liaoning province in Northeast China, and makes up the southwestern coastal half of the Liaodong region. It is located between the mouths of the Daliao River (the historical lower section of the Liao River) in the west and the Yalu River in the east, and encompasses the territories of the whole sub-provincial city of Dalian and parts of prefectural cities of Yingkou, Anshan and Dandong.
Bulkhead (partition)A bulkhead is an upright wall within the hull of a ship or within the fuselage of an airplane. Other kinds of partition elements within a ship are decks and deckheads. The word bulki meant "cargo" in Old Norse. During the 15th century sailors and builders in Europe realized that walls within a vessel would prevent cargo from shifting during passage. In shipbuilding, any vertical panel was called a head. So walls installed abeam (side-to-side) in a vessel's hull were called "bulkheads".
GalleonGalleons were large, multi-decked sailing ships developed in Spain and first used as armed cargo carriers by Europeans from the 16th to 18th centuries during the age of sail and were the principal vessels drafted for use as warships until the Anglo-Dutch Wars of the mid-1600s. Galleons generally carried three or more masts with a lateen fore-and-aft rig on the rear masts, were carvel built with a prominent squared off raised stern, and used square-rigged sail plans on their fore-mast and main-masts.
Samudera Pasai SultanateThe Samudera Pasai Sultanate ( كسلطانن سامودرا ڤاساي), also known as Samudera or Pasai or Samudera Darussalam or Pacem, was a Muslim kingdom on the north coast of Sumatra from the 13th to the 16th centuries. The kingdom was believed to have been founded by Merah Silu, who later converted to Islam and adopted the name Malik ul Salih, in the year 1267 CE. Little evidence has been left to allow for historical study of the kingdom.
Economy of the Song dynastyThe economy of the Song dynasty (960–1279) in China was the wealthiest economy in the world during its time. The dynasty moved away from the top-down command economy of the Tang dynasty (618-907) and made extensive use of market mechanisms as national income grew to be around three times that of 12th century Europe. The dynasty was beset by invasions and border pressure, lost control of North China in 1127, and fell in 1279. Yet the period saw the growth of cities, regional specialization, and a national market.
