What Or Whom Does This Column Commemorate?

[SteveD]

In the middle of the roundabout in front of the Cambridge Theatre at the junction between Earlham Street and Monmouth Street in London's West End is a column. What or whom does it commemorate? On Google Earth, the inscription is just too faint to make out. Thanks for any help.

[grasscarp]

7 Dials sundial pillar
http://en.wikipedia.org/wiki/Seven_Dials