资讯

BBC3 年
Map symbols, direction and contour lines
A four-point compass can give a rough direction whereas a sixteen-point compass is much more precise. Map symbols show what can be found in an area. Each feature of the landscape has a different ...
Smith College4 天
Compass, China, 220 BCE
Earliest records show a spoon shaped compass made of lodestone or magnetite ore, referred to as a "South-pointer" dating back to sometime during the Han Dynasty (2nd century BCE to 2nd century CE).