In grateful appreciation we dedicate this series and these volumes to Cecilia Payne-Gaposchkin, who, with Sergei, set the spirit of empirical-theoretical atmospheric modeling by observing:

"All true variable stars have variable atmospheres, but a variable atmosphere is probably the property of all stars, whether obviously variable in brightness or not [as witness the solar envelope]";

and who, by her intimate knowledge of particular stars, pioneered in the recognition of the fundamental importance of "individuality of stellar atmospheric characteristics."

To Daniel Chalonge, who sought, by ingenious meticulous observations, to make quantitative the features of qualitative classical taxonomy, thereby laying the foundations of showing the inadequacy of its twodimensional, single-region atmospheric, character; and who always opposed the spirit of a distinguished theoretical colleague's remark:

"Don't show me those new observations of yours; they inhibit the range of my speculations."