Read the excerpt from "Ship's Chronometer from HMS Beagle." These were enormous and belief-shattering ideas for many people in the nineteenth century, but time was also changing in a much more day-to-day, or rather hour-to-hour, way. Thanks to clockmakers like Earnshaw, precise and reliable clocks and watches became ever more affordable. Before long the whole of Britain was running by the clock, and the measurement of time had been severed from the natural cycle of days and seasons. The clock ruled every aspect of life – shops and schools, pleasure and work. As Charles Dickens wrote, ‘There was even railway time observed in clocks, as if the sun itself had given in.’ Which central idea is best supported by the details in the excerpt?