Fuel consumption, assumed to be equivalent to the authors' "amount of dead biomass combusted" which consisted principally of surface litter and downed, dead woody fuels, was measured by pre- and post-fire weight sampling. All four plots were ignited to advance as surface head fires. The quantity "burn duration" quoted by the authors has units of
seconds per metre, not seconds per square metre and, as suspected by Van Wagner and Methven (1978), is
actually the reciprocal of r in Eq. 1 since the plots were essentially square in shape (45 X 50 m). The component
variables and calculated frontal fire intensities in their appropriate units and terms for all four fires are
documented here for completeness (Table 1). Rate of spread is quoted in metres per second for clarity in the
calculation of frontal fire intensity.