Nice bonuses are sections on plate tectonics and comparing countries's sizes.
Coloring enables you to reach an unusual level of concentration and awareness as you work. The active quest for a solution to the problem of longtitude persisted over four centuries and across all of Europe. Lacking the ability to determine their longtitude, sailors were literally lost at sea as soon as they lost sight of land. In 1714 England's Parliament offered a huge reward to anyone whose method of measuring longtitude could be proven successful. The scientific establishment had spent centuries confidently mapping the heavens for a celestial answer.