Abstract :
The authors are to be congratulated on presenting two papers on a very difficult subject. Paper 1009C has honestly given the results of extensive experimental work, including the inconsistencies in Table 1. There is no doubt that this is a complex subject, blending as it does the disciplines of engineering, physics and chemistry with a multitude of variables. A simple explanation often is not enough, and I believe the suggestions given in paper 1009C are possibly insufficient to explain the behaviour in service or the results of some of our own experiments