1.Previous
3.Next

century saw a steady increase in the number of places whose longitude had been determined with reasonable accuracy, often with errors of less than a degree, and nearly always within 2° to 3°. By the 1720s errors were consistently less than 1°. At sea during the same period, the situation was very different. Two problems proved intractable; the first was the need of a navigator for immediate results, and the second was the marine environment. Making accurate observations in an ocean swell is much harder than on land, and pendulum clocks do

1.Previous
3.Next