Link-boys performed a vital service in many English cities in the days before streets the routine gas-lighting of streets. One would be hired for a small fee to walk in front of you holding a flaming torch, usually ahead of your sedan chair, to light your way through the dark and often dangerous streets.

The term derives from "link", a term for the cotton tow that formed the wick of the torch. Links are mentioned in William Shakespeare's “Henry IV, part 1”, as Falstaff teases Bardolph about the shining redness of his face: "Thou hast saved me a thousand marks in links and torches, walking with thee in the night betwixt tavern and tavern." (Act III, scene 3)

Several houses in Bath, and many in London still have link extinguishers on their exteriors, cone-shaped like outsized candle snuffers – one of these is seen in the accompanying picture.

The link-boy has a curious modern echo. The small Scottish town of Moffat has experimented with switching off artificial lighting to reduce light pollution and, in 2016, became the first European town to receive International Dark Sky Place certification. During the periods of the experiment the streets are intensely dark. Visitors coming out of pubs in the evening are surprised to be greeted by teenagers with paper lanterns who enquire “do you need a link?”

More Info: en.wikipedia.org