Smith and James (1978) refer to four types of intensity: fireline, bum, burning, and fire. The latter three are used interchangeably to denote fire temperatures. The "fireline intensity" denoted in Table 1 of their paper is most commonly termed Byram'sJireline intensity in literature from the United States (Albini 1976) The preferred term in Canadian forest fire research and management isfrontalJire intensity (Canadian Committee on Forest Fire Control 1976; Van Wagner 19776,1978) which distinguishes between line fire intensity and area-fire or reaction intensity (IR). IR is the rate of heat release per unit area in the active combustion zone (kilowatts per square metre)