The compass was invented in China during the ninth century to be able to sail in the open sea. During the second half of the fifteenth century it was given a different use. The miners started using it to do underground work. It is considered the most used element in navigation from the fifteenth century.
An economic historian would not research the style of dress the Queen wore to court most often, as it does not have much of an effect on economics as a whole in that time period.
