Hello Bill,
My interpretaion.........
Mobilised at Athlone 6th August 1914
Posted to 21 Battery, II Brigade RFA, 7th August 1914 [He went to France 11th September ]
Posted to 5B Reserve Brigade (Edinburgh) 7th November 1915 [Home]
Posted to 4a Reserve Brigade (Woolwich) 6th December 1915 [Home}
Posted to 21 Battery, II Brigade, 13th December 1915 [France]
Remained with 21 Battery until posted to 42 Battery (still within II Brigade), 1st December 1917.
The last overseas posting on 17th Oct or Nov 1918, I can't work out, but I think that it may be 276 Battery, but I haven't been able to track it down.
II Brigade was a Regular Army Brigade attached to 2nd Division.
http://www.1914-1918.net/2div.htmDo you have his medal index card?
Phil