1.   If the mortar has no crew at all it is unable to fire.

2.   Make sure any old mortar has bee cleaned off the stonework before using new mortar.

3.   But by reaching Israeli towns that for decades had been considered safely beyond the conflict zones, the mortars had a substantial psychological effect.

4.   The mortar had to be buttered generously over the stones to make the joints appear wider.

5.   The Palestinian mortars have a range of about a mile.

6.   Though modern mortars have gun sights, the homemade ones are just tubes pointed up at an angle.