mobileWestminster Tide Recorder
The turret in front of you is called the Westminster tide recorder (pictured). It
measures the depth of the Thames at this point. You can climb up the rails
on the side of the turret and look inside to see the computerised depth
reading.
The Thames is the second oldest place name in England. For 400 years, it was the busiest road in England,
like the grand canal in Venice, as the easiest way to cross London was
by boat. In fact, until the 1750's, there was only one bridge across the
Thames within central London: London Bridge.
Look across the river to the wall on the opposite side. You will see
a number of lions' heads facing the river, with mooring rings hanging from their mouths. They are part of London's flood warning system and every policeman on duty near the river keeps an eye on them.
Although the Thames Barrier has reduced the risk, the phrase "When the lions drink, London's in danger" is still true. If the water reaches the lions' mouths, the Thames is at danger level and the tube system and all Thames tunnels would be closed.
Did You Know?
Many historians believe that the Romans, who settled London around AD43, used to cross the river near this point. They think the actual crossing point was on the other side of Westminster Bridge, in front of St Thomas' Hospital, as during Roman times, this section of it was no more than waist deep.