The Need for Codes

Semaphore operators usually returned to the ready position after each signal so that individual letters were easier to pick out from a distance. Click here to learn semaphore yourself!

Smoke signals, beacon fires, waving flags and flashing lights have been used for centuries to communicate over distances beyond the limited range of even the loudest voice. From simple alarm signals like hilltop fires used to announce impending invasion, more elaborate codes were developed which could convey complete text messages.

Image: A fire beacon used to signal to soldiers on a distant hill top.

It was the discovery of electricity that changed the way people communicated. Charles Wheatstone's Five Needle Telegraph was an early receiver. Its needles deflected to the left and right and pointed to one of 20 letters.

Early systems were designed to appeal to industry by making the operators' lives as simple as possible - they spelt out the messages. It wasn't until businessmen accepted the commercial potential of telegraph that the system was simplified - the code proposed by Samuel Morse in the 1830's eventually became de facto world standard, which is still in use today.

Image: Samuel Morse, inventor of Morse Code.

Click here - you can learn Morse yourself!