First of all I would like to thank our hosts from the University of Washington and from the Boeing Airplane Company. In particular, Dr. James Drummond has labored indefatigably for many months to bring about this conference. I think we have all been impressed by the program he has provided for us and by the general excellence of the papers presented at this meeting. In fact this very excellence provides me with a considerable problem since this field is so diverse and has been so well covered by the preceding speakers. I am faced by a sort of insoluble “many‐subject” problem which I can only treat in a very cursory fashion which may best be described as the Random Phrase Approximation.