That is the dangerous wound.

He said he did not feel much pain.
The wounded were taken down to the tents set up in the ravine of the Port Road between the Headquarters and the old camp.

That is the main hospital (11th and 18th) since the wounded were shifted out of the Town Hall, because the Boers shelled it so persistently.

Since the Geneva flag was removed from the hall's turret not a single shell has been fired near the building.

The ravine--"kloof" is the word here, like "cleft"-- is fairly safe from shells, though the Bulwan gun has done its best to get among the tents ever since spies reported the removal.
It is fully exposed to those terrible dust storms which I described in an earlier letter.