Read the following passage carefully and answer the questions based on your understanding:

Telecommunications (literally : communications at a distance) are always critical to human society. Even in ancient times, governments and military units relied heavily on telecommunications to gather information and to issue orders. The first type was with messengers on foot or on horseback; but the need to convey a short message over a large distance (such as one warning a city of approaching raiders) led to the use of fire and smoke signals. Using signal mirrors to reflect sunlight (heliography) was another effective way of telecommunication. Its first recorded use was in ancient Greece. Signal mirrors were also mentioned in Marco Polo's account of his trip to the Far East. These ancient visual communication technologies are, amazingly enough, digital. Fires and smoke in different configurations would form different codewords. On hills or mountains near Greek cities there were also special personnel for such communications, forming a chain of regenerative repeaters. In fact, fire and smoke signal platforms still dot the Great Wall of China. More interestingly, reflectors or lenses, equivalent to the amplifiers and antennas we use today, were used to directionally guide the light farther.

Naturally, these early visual communication systems were very tedious to set up and could transmit only several bits of information per hour. A much faster visual communication system was developed just over two centuries ago. In 1793 Claude Chappe of France invented and performed a series of experiments on the concept of 'semaphore telegraph'. His system was a series of signalling devices called semaphores, which were mounted on towers, typically spaced 10 km apart. (A semaphore looked like a large human figure with signal flags in both hands.) A receiving semaphore operator would transcribe visually, often with the aid of a telescope, and then relay the message from his tower to the next, and so on. This visual telegraph became the government telecommunication system in France and spread to other countries, including the United States. The semaphore telegraph was eventually eclipsed by electric telegraphy. Today, only a few remaining streets and landmarks with the name Telegraph Hill' remind us of the place of this system in history. Still, visual communications (via Aldis lamps, ship flags, and heliographs) remained an important part of maritime communications well into the twentieth century.