. For the purpose of estimation of maxima, the

classes are not of very great importance, as few of the maxima under present investigation occur there, but the irregularity at

may well prove to be serious. There is indeed a general tendency for the intensity of, metallic lines to increase at

. All the

stars measured were of very high luminosity, and probably the rise of intensity is due to this feature, or rather to the increase of material above the photosphere that accompanies it. A maximum is only assumed to occur at