Time Ball dropped daily at 1 o'clock as a visul signal for shipping. Nine years later they added a Gun for foggy days.Knowing the time accurately was essential to enable navigators to work out longitude, to plan the shortest and safest routes around the globe on the trade routes that generated the wealth of the Empire and financed the industrial revolution. Astronomers calculated the time at observatories and the innovatory time balls of the nineteenth century allowed ships' captains to set their chronometers from a distance, without actually going to the Observatory. The recently conserved time ball on the Nelson Monument, Calton Hill, is a classic example by a fine manufacturer (Maudslay,Sons and Field), in near original condition, conserved to the highest standards, and supported in its day by one of the prominent astronomers of the 19th century, Charles Piazzi Smyth, who helped devise and install it in 1852. Piazzi Smyth continued to work out the time and triggered the ball drop himself. He even devised an automatic system to drop the ball.
Time Ball dropped daily at 1 o'clock as a visul signal for shipping. Nine years later they added a Gun for foggy days.