The mystery of the weird symbols of Uxbridge has certainly got you talking, and now we think you might have cracked it.

Reader Maria Speechley alerted us on Monday to one of the marks – a square central dot with radiating triangles, resembling a windmill’s sails or a stylised sun – at the junction of Grove Road, Uxbridge and Grove Way.

“No one seems to know what it is for and I have not noticed any others in the immediate vicinity,” she said.

There is another of the white, spray painted symbols in the pedestrianised section of Uxbridge High Street, close to Lloyds Bank, and the Gazette took some video to show the location.

When we posted the story online it created a huge buzz of interest, as thousands of you had a quick look. Readers got in touch via Twitter, Facebook and YouTube to share their theories.

Mongomay1 posted on our YouTube video : “Might be survey markings to allow remapping of public utilities or the roadways.”

And reader Dave Hill via Facebook, with a nod to another story we ran this week, commented: “Could it be messages for illegal raves?”

Tarnya Gibson asked: “Could it be bank robberies?” Unlikely, as one of the symbols was in a residential street a long way from any banks, and Hillingdon Police discounted the theory of them being ‘burglar signs’ yesterday (Thursday).

Reader Jackie Cubitt plumped for the simplest answer in a one-word posting: “Graffiti.”

However, one theory – that the symbol is the location point for a surveyor’s theodolite – had been disregarded because theodolites are mounted on tripods, not a single leg.

However, it now seems that might be the answer, as the picture below shows.

And it was getwestlondon.co.uk blogger Scott Balcony who came up with the most confidant and cheekiest suggestion so far.

“It is called a flight cross,” he declared, despite no evidence of the existence of such a thing.

“It is a survey marker used for aerial photography and mapping.

“Do I win £5?”

As this picture testifies, the Gazette fiver might be winging its way to Windsor Street, although you would need good eyes to see the one in our video from an aircraft.

Thank you to everyone who got in touch to share their theories.

If there is anybody out there who sprayed these symbols, uses them in their daily work – and wants to rob Scott of his winnings – please get in touch.