There are three major families of shorebirds: 1  Waders, about 220 species, include sandpipers, lapwings, snipes, plovers, stilts and various other species. These birds inhabit coasts and shorelines, as well as other open habitats. 2  Gulls, terns, skuas, jaegers and skimmers form a group of a little over 100 species.
The compass was probably invented in the Qin Dynasty (221-206BC) by Chinese fortune-tellers who used the lodestones to construct their fortune telling boards.
The compass was invented in China during the Han Dynasty between the 2nd century BC and 1st century AD. The magnetic compass was not, at first, used for navigation, but for geomancy and fortune-telling by the Chinese.his is an approximation of a milli-radian (6283 per circle), in which the compass dial is spaced into 6400 units or mils for additional precision when measuring angles, laying artillery, etc. The value to the military is that one angular mil subtends approximately one metre at a distance of one kilometer.