Intrigued tourists watch as Paul Doy climbs a ladder outside London's Westminster Abbey and lifts the globe of a gas street lamp.
Winding its timer, he then ignites a small cloth mesh, creating a distinctive soft warm light that illuminates the darkness.
"I like the historical aspect of it," said Doy, even if it means getting up at 5:00 am to tend to the lamps in the fashionable district of Covent Garden.
"It's mainly winding the 100-year-old mechanical clocks" in the lamps "and setting the times for those, especially now as well, because we're losing light much earlier," he told AFP.
The 200-year-old nightly ritual nearly became history, however, over local authority plans to replace 174 gas-powered lamps protected by a heritage order with eco-friendly LED bulbs.
The plan by the City of Westminster council caused uproar among some residents and heritage lovers, and even sparked a question in parliament.
But on Tuesday, the council said it had decided to scrap the move. Instead, it will convert 94 other gas lamps which are not protected.
Tim Bryars, who owns a small bookshop in Covent Garden, stumbled across the plan by chance just over a year ago.
"One morning, I went out of my shop, there are a couple of guys from the council digging a hole in front of my bookshop," he said.
"I said, 'what are you doing?' And they said, 'Don't worry, we're just looking to see how easy it will be to convert your gas lamps to electricity'.
He fronted a campaign to save them and on Wednesday called the council's U-turn "a good first step".
"Basically they are admitting we were right but they have to do more," he told AFP.
"We actually need a firm policy commitment to positively preserving the gas lamps, not just keeping a few until they become troublesome."
- 'London's DNA' -
London has more than 1,000 gas street lamps, which were installed at the beginning of the 19th century.
At the time, they were considered a major innovation in a city with dark, dirty and often dangerous streets.
In central London, they still light up parts of The Mall avenue leading to Buckingham Palace, the back streets of Covent Garden, and around Westminster Abbey.
The atmospheric light they give out is evocative of Charles Dickens novels, Mary Poppins and Sherlock Holmes.
"They are an incredibly important part of the fabric of London's history. They are in London's DNA," said Luke Honey, an antiques writer who was also involved in the campaign.
"They are just beautiful things. The quality of light is incredibly natural," he said in Goodwin's Court near Covent Garden, said to be the inspiration for Diagon Alley in J.K. Rowling's Harry Potter series.
"I am afraid reproduction LEDs just don't replicate the beauty of original lamps and also the quality of that particular gas light."
Joe Fuller, head of the maintenance team for old street lamps at British Gas, accepted that some of the replacements "look very nice".
"But they're still different from the originals," he said.
"I think it's really key that we maintain that heritage and keep as many as we possibly can."
- Consultation -
Previous attempts to replace the gas lamps caused a similar outcry and forced the council to abandon its plans.
But a change of leadership revived the project, as part of an overall aim to reduce carbon emissions -- and improve public safety.
The council had been trying to convince naysayers in a public consultation exercise, which ended on Sunday.
Paul Dimoldenberg, the council's cabinet member for city management and air quality, said the lamps were "increasingly difficult to maintain and repair".
"In a street where gas lamps break down... the streets are in darkness for longer, and therefore they are not as safe as they should be for pedestrians or anybody using the streets in the dark," he added.
But in abandoning the move, he said the council acknowledged "the strong heritage issues at stake".