Finding that any direct assault was to open to the fire of the defenders, Te Rauparaha set his men to sap up to the walls. At first many were lost in this work, but by covering the trenches, and breaking their line with zig-zags, the head of the sap was at last brought to within a few feet of the pā. large quantities of manuka brushwood were then cut, tied in small bundles, taken to the head of the sap, and thrown into the trench against the palisades. For a time, the defenders were able at night to remove the greater part of this brushwood, but in the end the quantity was greater than they could deal with. Realizing that with the first southerly wind the invaders would fire the brushwood and thereby burn down the palisades, the Ngāi Tahu tried the desperate expedient of firing it themselves when the wind was nor’west, and driving away from the pā.