The 'Secret' Telescope

When I first heard the story about there being a massive 17th Century telescope hidden in Central London I assumed it was an urban myth. Nope, turns out it's true!

The Monument is a 202ft column made from Portland stone. It was built in 1677 to commemorate the Great Fire of London and stands at the junction of Monument Street and Fish Street Hill in Central London. The doric column contains a spiral staircase leading up 311 steps to a viewing platform 160ft up that gives spectacular views across London. The column is topped with a flaming golden orb. The Monument was designed by Sir Christopher Wren and his friend Dr Robert Hooke. Wren was involved in redesigning many parts of the City after the Great Fire. Hooke was a scientist who wanted to use astronomical parallax to prove that the Earth goes around the Sun. To do that he needed a very large, very stable telescope...

I decided to 'fact-check' the story so I contacted the official Monument website. I had a quick reply - 'In addition to being a monument to the Great Fire of London, the Monument was also designed by Robert Hooke to be used as a telescope.'

A trap door in the ticket office leads down to a basement area. At one time this would have been Hooke's secret laboratory. From this room there is a clear view right to the top through the centre of the spiral staircase. Hidden inside the flaming orb at the top is another trap door. Lenses would have been slotted in at the top and bottom of the column and, with the trap doors open, Hooke would have been able to take precise observations of the night sky from his basement lab. Well, that was the plan. Unfortunately for Hooke the Monument was situated next to one of the busiest roads in London. Vibrations from the traffic ruined his experiment.

Hooke did use the Monument for other experiments though. Each step in the staircase is exactly six inches tall and he used this to precisely track changes in atmospheric pressure between top and bottom.

So yes, there is a massive 17th Century telescope hidden in Central London - go take a look if you don't believe me.

all rights reserved by Slightly Washed Out Goth

https://www.themonument.org.uk/aboutus/
http://www.bbc.com/future/story/20170810-the-medieval-lab-hidden-inside-a-famous-monument
https://londonist.com/podcasts/londonist-out-loud-the-great-fire-and-the-monument

https://commons.wikimedia.org/wiki/File:The_Monument_to_the_Great_Fire_of_London.JPG

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