Longitude of the moons of Jupiter one could use their positions as a universal clock and this would make possible the determination of longitude, but the method he devised was impracticable for navigators on ships because of their instability. In 1714 the British government passed the Longitude Act which offered large financial rewards to the first person to demonstrate a practical method for determining the longitude of a ship at sea. These rewards motivated many to search for a solution. John Harrison, a self-educated English clockmaker, invented the marine chronometer, the key piece in solving the problem of accurately establishing longitude
How Many Miles to Babylon? (novel) and careful description" to depict the chaotic environment created by war. The novel also includes small abstracts from poetry and songs. The title of the novel is derived from a traditional nursery Rhyme, How Many Miles to Babylon?: <poem> </poem> When re-reviewing the novel in 2011, Philip Womack described the novel as "slim but emotionally hefty." For Womack, it's a poignant retelling of how the First World War erased lines of class, and its emotional toil: "Johnston's novel conveys both the insanity of war and the poignancy of unspoken tenderness." In 1982 it was adapted for television by the BBC,