58355: 3 soldiers relaxing under a tree

Postcard sent by Robert James Beadon to his mother, (my great aunt I think, I found this in a box of photos when my aunt died.) I don't know which of the three soldiers he is.

It reads "This is how we are compelled to walk about owing to the heat, I don't know what it will be like when we get the other side of the Mountains 'Caucasus' as we soon shall be now"

I think he must have been going to Mesopotamia because I found this on the the Commonwealth War Graves Commission website -
In Memory of Serjeant ROBERT JAMES BEADON
79686, 6th Light Armoured Motor Bty, Machine Gun Corps (Motors)
who died age 29 on 15 October 1918.
Son of Robert James and Ellen Beadon, of 1, Brook Rd., Wood Green, London.
Remembered with honour BASRA MEMORIAL