The recently published National Fire Protection Association code on smoke control includes the result obtained by Morton, Taylor and Turner in their classic paper for the height an axisymmetric plume will rise in an atmosphere with a density linearly varying with height. No comparable result for a two-dimensional line plume appears in the conventional fire literature, although the problem has been solved by Strothers in a different context. This Fire Note applies the work of Morton et al to a two-dimensional plume. Some comments are made concerning a non-linear temperature or density gradient in the surroundings. The theory gives a lower bound for this non-linear stratification.