An Act of Parliament in 1555 formalized the trade by setting up a company to govern tariffs and reduce accidents. The new company had jurisdiction over all watermen plying between Windsor (in Berkshire) and Gravesend (in Kent). The Act empowered the London mayor and aldermen to yearly choose eight of the "best sort" of watermen to be company rulers, and to make and enforce regulations. It also specified a seven-year apprenticeship in order to gain an encyclopaedic knowledge of the complex water currents and tides on the Thames. Watermen freeman were now required to pay "quarterage", or paid quarterly contributions. This was a constant source of grievance and dispute with company rulers who were frequently accused of taking bribes to "free" apprentice watermen.