With the renewed prosperity of Mediterranean trade and the revival of ancient geographical knowledge，End bet365 bonus code louisiana 13th century，Genoa、The earliest nautical illustrated books in Western Europe appeared in places such as Venice and Catalonia。The nautical illustrated book is a navigation guide with pictures and texts，The theme is color chart，Decorated with ship、Sea Monster、Flag、City and other patterns，And insert instructions in important places。The nautical illustrations of Western Europe from the 13th to the 15th centuries are regarded as "one bet365 bonus code louisiana most important turning points in the history of maps"。This is because，Compared to other navigation guides in the ancient world，It has the following outstanding features。

　　First, bet365 bonus code louisiana has strong practicality.Compared to other navigation guides in the ancient world，The most obvious feature of Western European nautical illustrations from the 13th to 15th centuries is the marking of equiangular routes、Compass dial、Wind Rose Chart and Scale。During the voyage，Seamen follow the equiangular route，The destination port can be reached without changing a certain azimuth angle，Helps plan sailing routes in advance。Congruent courses need to be used in conjunction with the compass dial。The original compass dial in the illustrated book only had 4 directions。Gradually developed later，Reached 32nd position in the second half bet365 bonus code louisiana 16th century。The wind rose diagram represents the frequency of various wind directions、Average wind speed and maximum wind speed，According to different requirements bet365 bonus code louisiana objects used，Younian、Quarter, month and other types。The wind rose chart uses specific colors to represent different wind directions，When the main wind direction cannot be grasped，Navigators can use the wind direction chart to choose a relatively correct course。Nautical illustrations often use linear scales，Navigators can judge the sailing distance between different areas based on illustrations and scales。In addition，Focus for voyagers，The painter has given special treatment to different landforms: marking important cities in red，Color the islands with different colors、Distinguish the delta from different surrounding landforms，Or use specific colors or flags to indicate the political status of a place。For example，The white cross flag on a red background represents the territories of Rhodes and Malta bet365 bonus code louisiana Knights Hospitaller。To meet the practical needs of voyagers，The producer does not hesitate to sacrifice local accuracy，By simplified or exaggerated depiction，Highlight the coastline、Important Islands、Capes and coastal rivers and other landforms。After these processes，"In the nautical illustrated book，All trivial and useless elements have been removed”，Achieved “the most realistic depiction bet365 bonus code louisiana world”。

　　Secondly, most bet365 bonus code louisiana information comes from navigation practice.The main purpose of Western European nautical illustrations from the 13th to the 15th centuries was to guide sailors on their sea voyages。Therefore，Accuracy is a navigator’s basic requirement for illustrations。Due to the personal experience of most producers、Timely updating of navigation knowledge and accumulation of cartographic technology over the years，The accuracy bet365 bonus code louisiana illustrations has been greatly improved。First，Many producers have directly participated in maritime navigation or engaged in activities closely related to the ocean。The long-time captain Gracioso Benincasa, known for his prolific output，His son Andrea Benincasa also has the dual identities of illustrated book maker and captain。Cartographer Andrea Bianco served as Captain Flanders for 15 years。Antonio Pellecian, the maker bet365 bonus code louisiana 1459 illustrated book, calls himself the "Manager bet365 bonus code louisiana Port of Lutmore"。Visconti, the most famous early cartographer, served as Venice's maritime advisor。Secondly，Division of labor and cooperation in the production process。Due to the huge workload of making illustrations，Division of labor and cooperation are inevitable。Some illustrations indicate the names of multiple creators。Even if only one person is marked，Writing、marked red、Coloring、Painting and other work are also completed by many craftsmen。June 1399，The Florentine merchant Ubriacci commissioned the Mallorcan Jewish cartographer Crescus and the Genoese painter Beccari to produce 4 nautical charts。Clearly stipulated in the contract，The former draws the base map，The latter decorates and polishes the base image。Division of labor and cooperation allow producers to focus on a specific area，Effectively ensures the standardization and accuracy bet365 bonus code louisiana illustration。Again，To a place that cannot be visited in person，The producer will try to obtain more accurate information from witnesses or professionals。In "For Readers" of an illustrated book，The producer specifically stated how to obtain the materials。He said: “The above content is based on the producer’s personal experience and the reliable accounts of many people，Including captains from the Spanish Sea and related waters、Ship Owner、Sailors and Navigators。They are good at sailing，Sailing in these waters for a long time or frequently。”It is precisely because the mapmaker’s information source is reliable，The accuracy bet365 bonus code louisiana illustrated book is guaranteed。Even if it is inappropriate occasionally，Producers can also quickly get feedback and make timely corrections。So he added: "Many captains are skilled in the art of navigation、Ship owners and sailors told me，Sardinia is not drawn in the correct place in the illustration。Therefore，In the name of my Lord，Currently in this illustrated book，The island has been placed where it belongs。”Finally，With the advancement of maritime exploration and the emergence of new problems in navigation，The producer will update the content bet365 bonus code louisiana illustrated book in due course。In early nautical illustrations，There are only 16 equiangular routes。In order to avoid large deviations in estimating bearing and distance due to insufficient number of equiangular routes，Cartographers in the early 15th century increased the number of equiangular routes to 32。In addition，With the development of offshore business，Navigators need to know the specific locations of more cities and towns around the ocean。For this，The illustration depicts specific areas in more detail。For example，In an illustrated book from 1313，There are only 36 place names in the British Isles，Increased to 49 in 1320，More than 60 in 1327。Illustrated books that are not updated in time will be scrapped soon，Becoming a worn-out sheepskin “nailed to a broken doorframe”，Or cloth strips for binding books。

　　Third, have a certain scientific bet365 bonus code louisiana.On the one hand，Religious content takes a back seat。Affected by the times，Although nautical illustrations cannot completely escape the influence of theology，But regardless of Prester John、Blessed Land、Onishi Island or other mythological content，are placed to indicate inland or edge places。The coastline that navigators pay most attention to、Contents such as equiangular routes will not be disturbed at all。On the other hand，The descriptions in some nautical illustrations reflect a strong spirit of academic criticism。For example，When discussing the dividing line between Asia, Africa and Europe，The nautical illustrations of Fra Mauro in the mid-15th century provided insightful refutations of various views。In the sixth description，He first sorted out the representatives and views bet365 bonus code louisiana two schools，Then analyze the two schools of scholars based on the Nile River、Tanais River and the Red Sea、The reason why the Edir River is the boundary river。Finally the producer clarified his views and reasons。In fact，The producer’s discussion on the demarcation bet365 bonus code louisiana three continents has gone beyond the basic function bet365 bonus code louisiana illustrated book as a navigation guide，Possess the basic framework of modern academic criticism。As you can imagine，Some makers have transformed from skilled craftsmen who drew illustrations to experts with profound knowledge。The theoretical literacy of some Western European navigators may also exceed people’s imagination。In other words，Before the geographical discovery，The accumulation of navigation knowledge by Western Europeans has reached the critical point from quantitative change to qualitative change。What happened next changed the course bet365 bonus code louisiana world and opened up a new route，It is just the result bet365 bonus code louisiana natural development of their navigation knowledge accumulation process。

Actually，Except Western European Nautical Illustrations，Records of maritime navigation directions also appeared in different parts bet365 bonus code louisiana ancient world、Sailing mileage and ports along the route、ethnic group、Customs、Works about political conditions and other contents。For example, the Zhou Hangji of ancient Greece and Rome、Book of needle routes (regular routes or water routes) in the East China Sea and South China Sea, etc.。Although these works have some characteristics of navigation guides，But its actual role in navigation still needs to be further investigated。Compare with，13th-15th Century Western European Nautical Illustration，Due to the use of equiangular routes、Scale、Compass dial、Wind rose chart and other means of determining position and speed，And mark and depict specific features through different colors，The content is clear at a glance，It is helpful for navigators to quickly judge the position and the upcoming situation，To formulate an appropriate sailing plan。simultaneously，The reliability bet365 bonus code louisiana producer’s data sources and the scientific spirit upheld in the production process，Making the accuracy and applicability of nautical illustrations before the geographical discovery far beyond any previous era。Needless to say，Some parts bet365 bonus code louisiana illustrated book may be out of proportion or distorted。But overall，The seafarers’ recognition and reputation for it are unmatched by other similar works。Efria Çelebi, a traveler from the Ottoman Empire, said: "Nautical illustrations are a science，Is the soul of navigation。The voyager is following the instructions in the illustrated book，Sail on the ocean。”That’s why，Western European nautical illustrations were translated into Arabic，Welcome by Islamic voyagers，Widely used in navigation in the Mediterranean and Indian Ocean。Anyway，The Western European nautical illustrations that appeared at the end bet365 bonus code louisiana 13th century can be described as a navigation guide with real practical value，Prepared for knowledge accumulation and technical preparation for the upcoming geographical discovery and the opening of new shipping routes。

(The author is a professor at the School of bet365 bonus code louisiana Development and Public Administration, Suzhou University of Science and Technology)