The author was of the opinion that the locomotive boiler described in the Letter to the Editor by H Canning in The Engineer, vol. 57, 30 May 1884, p. 405, had an unusually thin fire-box tube plate further weakened by having the tubes pitched very close together and surrounded by a rigid frame. At the top there were direct screw stays to the shell plate just where the latter was stiffly connected to the barrel by the vertical front plate of the firebox. At the sides there were the usual copper stays to which the same remarks applied. At the lower part the depth of the plate beneath the tubes was very slight, it was also straight and riveted directly onto a heavy foundation ring and was further stiffened by very short palm stays. Leakage occurred during rapid steaming trials because there was insufficient 'elbow room' to cater for the expansion of the various components of the boiler.