The engine fired at the first turn and Nicholas hooted, 'Full marks,
Sapper. All is forgiven.'
He gave the machine time to warm up to optimum operating temperature,
slitting his eyes against the rain as he waited and looking around at
the hills above him, fearful that the sound of the engine might bring
Nogo's gorillas swarming down on him. However, there was no sign of life
on the rainswept heights.
He eased the tractor into her lowest gear and turned her down the bank.
Below the dam wall the water that was finding its way through the gaps
was less than hub-deep.
The tractor bounced and ground its way through the boulder-strewn
watercourse. Nicholas stopped the machine in the middle of the river bed
while he studied the downstream face of the dam wall for its weakest
section.
Then he' lined up below the centre of the wall, at'the point where
Sapper had shored up the raft of logs with rows of gabions.
'Sorry for all your hard work,' he apologized to Sapper, as he
manoeuvred the steel scoop of the tractor to the right height and angle
before attacking the wall. He worried the gabion he had selected out of
its niche in the row, reversing and thrusting at it until he could get
the scoop under it and drag it free. He pulled away and dropped the
heavy wire mesh basket over the waterfall, then drove back and renewed
the attack.
It was slow work. The pressure of the water had wedged in the gabions,
keying them into the wall so it took almost ten minutes to free the
second basket. As he dropped that one over the waterfall, he glanced for
the first time at the fuel gauge on the dashboard of the tractor and his
heart sank. It was registering empty. Sapper must have neglected to
refuel it: either he had exhausted the fuel supply or he had not
expected ever to use the machine again when he abandoned it.
Even as Nicholas thought about it the engine stuttered as it starved. He
reversed it sharply, changing the angle of inclination so that the
remaining fuel in the tank could slosh forward. The engine caught and
cleared, running smoothly and strongly once again. Quickly he changed
gear and ran back at the wall.
'No more time for finesse,' he told himself grimly.
'From here on in it's brute force and muscle.'
By removing two of the gabions he had exposed a corner of the log raft
behind them. This was the vulnerable and part of the wall. He worked the
hydraulic controls lifted the scoop to its highest travel. Then he
lowered it carefully, an inch at a time; until it hooked over the end of
the thickest log in the jam. He locked the hydraulics and thrust the
tractor into reverse, gradually pouring on full power until the engine
was roaring and blowing out a cloud of thick blue diesel smoke.
Nothing gave. The log was jammed solidly and the wall was held together
by the keying of the gabions into each other and the enormous pressure
of water behind them. Despairingly, Nicholas kept the throttle wide
open.
The lugged tyres spun and skidded on the boulders under them, throwing a
