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This is the first post of what will be things I see on my walks around London on the same day.
Today I saw some manhole covers and associated them with others seen on yesterday’s walk.
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Some of you may have noticed the numerous ubiquitous, oblong, Post Office Telegraph covers. Well I noticed a certain evolution of covers that led to these.
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Originally they were Exchange Telegraph Company covers (commonly known as Extel, set up in 1872.) One can see the similarity in style with the small central grille. Clearly the later Post Office credited covers were based on Extel’s, but with  larger central grille. No doubt its how we got the common style of manhole cover we see all over London today.
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A bonus today was this London Transport manhole cover – the first one I’ve seen. – no doubt these are more rare than those for the LCC tramways.
Update 6 May 2017:
Following on from those manhole covers yesterday, here are some more I took pictures of today (6 May) which tell a little bit more of the story behind these Post Office covers.
These two covers can be seen near each other in Gower Street. Same company different style of ID.
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Those we saw yesterday would have likely evolved into this one at Gower Street. However…
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This one denotes the GPO (or General Post Office) which was abolished in 1969.
Usually the covers with the grille (or vent) are the older ones, and yes Post Office meant the GPO. The one with P.O. on it in St Martin’s Lane is actually a rarity, it seems to be a generic cover rather than a telephones or telegraph one.
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Some of the Post Office covers were just plain P.O.
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A larger type of Post Office manhole cover with grille of a different sort. Sometimes these grilles were off to one side.
This is not meant to be a definitive history of these manhole covers, just examples of how they evolved.