Turning Point Inventions Clock
By Trent Duffy.
Description
Today, surrounded as we are by clocks and watches, it is hard to imagine life without an exact method of timekeeping. Until the mechanical clock was invented and improved, people had a less precise sense of the passage of time, based largely on the movement of the sun across the sky and measured with sundials, sandglasses, and other simple devices. It wasn't until the eighteenth century that John Harrison invented a truly reliable clock. Harrison's final invention, H-4, was the first accurate and portable mainspring clock. Meanwhile, stationary timekeepers such as longcase (or gr...
ISBN(s)
0689828144, 9780689828140
