This chapter surveys the workings of the British Board of Longitude in the period from the mid-1770s, which saw expenditure and bureaucracy increase. The Longitude Act of 1774 cut rewards and tightened the criteria for success. Managed through a permanent secretary, the Board more resembled an office of state, while personal and patronage relations still played vital roles in its conduct. Both Astronomer Royal Nevil Maskelyne and Joseph Banks exploited the Board to further their own interests in policy and organisation in projects including management of the Nautical Almanac and its computers, supply of instruments to survey voyages, and trials of new kinds of optical glass. The chapter explains how Maskelyne used the Board to extend networks centred on the Royal Observatory, Greenwich, while Banks used his position as a Commissioner of Longitude to mend relations with the Admiralty and extend patronage. Although there were major tensions and conflicts with Maskelyne, Banks was able effectively to make the Board of Longitude an integral component of his system of public administration over the sciences.