I'm not an artillery buff but I'm sure it would help a lot if you told us where the photo was taken as details of UK and French batteries may well be a matter of record?
Sorry Brian, sounds a good idea. Couldn`t find how to add text after I`d added the photo. It`s at Budle Bay in Northumberland.
May have been a 4-inch ex naval gun according to WWII gun emplacement, Budle Bay:: OS grid NU1635 :: Geograph Britain and Ireland - photograph every grid square! www.aenvironment.co.uk/.../Northumberland%20Coast/0058-1_ is also very interesting but mainly about Druridge Bay. One site calls it a Hotchkiss gun emplacement and another a 6" gun emplacement - I can't find any reference to Hotchkiss 4 or 6inch ordnance, and it seems much more likely to have been a 4inch QF mark ix but I'm only saying that as I know they were installed as coastal defence near me at Crosby.Someone more knowledgeable is bound to be along soon. Good luck.
Thank you very much Brian, Sorry, but your second link dosn`t work. Would be very grateful if you could check it please.