 During the 18th century, the only way of summoning a servant was by calling, or a handbell.This meant a servant had to remain on duty within earshot at all times (straight-backed uncomfortable hall chairs designed to keep servants awake date from this period).However, the early 19th century invention of the bell pull, a complicated system of wires and chains within ceiling and wall cavities, meant a servant could be summoned from a greater distance, and therefore also kept at a greater distance.