diary:
http://www.rootschat.com/links/01hbx/ You want the 1915-18 diary.
I can save you the trouble as I've now found it.
It was included with the 10th's. diary.
The assault was larger than indicated in the 10th's diary & involved several Battalions.
It started on the 7th. July 1916. The 13th's. objective was to take over the old German trenches as far as the outskirts of the village of Contalmaison to the N.E. of La Boisselle which they successfully achieved but came under intense shellfire probably from Mametz Wood further to the East.
They reached their final objective on the evening of the 8th. July when they were relieved.
They returned to the old British line where they rested during the day of the 9th.
casualties:
Officers: 1 killed; 4 wounded.
O.R's : 20 killed; 127 wounded & 13 missing.
200 German prisoners taken.
Amongst the captured "trophies" as the men called them were 5,000 hand grenades which were stored in an ammo dump unfortunately it took a direct hit from a German shell. The report was that they exploded over several hours. It must have bee like some bizarre firework display. I'm sure it amused both sides.