Hooke's system is an early instance of telegraphy, that is, writing at a distance. An apparatus of poles and hooks allowed special characters to be hung and revealed, which could be observed over many miles using another 17th century invention, the telescope. In principle, a series of stations could convey messages over hundreds of miles at an unheard of speed. This optical telegraphy required not just clear and unobstructed line of sight, but a disciplined and attentive chain of observer/operators. It was never implemented by Hooke or his contemporaries; instead, the first functioning optical telegraph system was created in the first French Republic in 1794.