Outdoor 'light switch'

Funny how you only just notice things. On my way back from my regular check-up at the dentist I spotted the trumpet shaped features in the railings on Charlotte Square. I must have walked past that way hundreds of times without paying attention. They have the look of candle-snuffers. I looked them up and apparently they were used by the 'Link boys', in the days before proper street lighting in Edinburgh.
Back then the wealthier residents would hire someone to carry a flaming torch to light their way home at night. These were known as 'Link Boys' and when they reached their destination, they would want to snuff out the torch to save it for their next 'fare'. Hence the snuffers in the railings.
The name comes from the twisted strands of cotton used as a wick in the torches. Link Boys were also known as 'moon cursers' as there was less need of their help on moonlit nights. As well as helping pedestrians they were useful in guiding sedan chairs and carriages around the city, and sometimes even the city guard or firemen.

Information from the Edinburgh World Heritage Site website.

Also amuses me a little as a long time ago I wrote a short passage in my (unpublished) novel about a fictional Scotland that included a wealthy merchant paying 'bargers' to guide him through the busy streets. I read it out in our writing group and people assumed my researches had discovered the existence of this job, whereas I had just made it up. At least to the best of my knowledge.

As he turned the corner where the street followed the dog-leg in the canal, he could hear the hubbub from the docks. Ahead he could see a solid wall of people crowded onto the bridge at the end of the canal. Beyond them was the harbour basin, and the wharves where the boats would be tying up. He would have to hire a couple of bargers to force a passage through the crowd. As usual, a small group of them had gathered just before the bridge. He remembered how threatening they had looked the first time he had approached them. Tall, broad fellows in dark coats and black top hats. Now he was well known and several of them touched the rims of their hats in recognition. He went up to the front of the group.
"Two shillings, to get me to the Caledonia. An extra two if we get to her before she's finished tying up."
"Certainly, sir. Two extra, each?"
"Yes. As long as we reach her before she gets a rope ashore. She's coming in at..."
"...wharf six. Aye, sir, we know. Stay close now."
He was swept along between them, his eyes fixed on the long white ribbon trailing from the hat of the barger in front, conscious of and yet never pushed by the barger behind. The man in front seemed to carve open a space in the heaving mass of people for him to step into. As the three of them passed through, the space then instantly closed up behind them. He could see that some of the other ships had already docked. When they got down onto wharf six, the masts and flags of the Caledonia were visible high above the heads of the crowd, but still moving, as the ship manoeuvred into position out in the tideway. The bargers would get their four shillings, as he had thought they would. He didn't like to set impossible targets, not like some of the others. Ross Mackay would always berate him for wasting his money.
"You give them too much. Let them really earn their meagre pennies."
On the other hand, Mackay didn't hear what the bargers had to say about him, and didn't appear to notice how they all tried to avoid his gaze when he approached their group by the little bridge. He was not a popular fare, and while the opinions of the bargers counted for nothing in merchant society, Roderick still preferred to do things his way. If he, Roderick Dickson, merchant of Montrose, could not afford to spread a little of his good fortune, on Convoy Day of all days, well, it had come to something. And, in any case, it wasn't entirely wasted. A favourable reputation with the bargers meant they would do that little bit more for you. He was never left across a street from the entrance to his club and forced to struggle the last few yards through the throng. They took him right up to the door, however busy the crowd. Or like today, they would stand, keeping the crowd from his back until one of his ships had tied up and he was ready to meet the captain. They never knew. It might get them an extra shilling.