THE contents of a technical journal such as AIRCRAFT ENGINEERING are of necessity indicative of current thought. Its pages at any given time reflect the problems that are confronting designers and the doubts that may be perplexing them. At the same time, they give a picture of the manner in which progress is being made and the order in which various aspects of design are one by one tackled and dealt with. That this should be so is inevitable, but perhaps in a greater degree even than the generality of readers realise. An editor can, of course, to a considerable extent influence the contents of his pages. But in fact, once it has attained an established position and reputation, his task is largely, and even mainly, one of selection. His principal occupation is to separate the wheat from the chaff and choose from among the considerable number of articles submitted to him those which are, in his opinion, of a technical standard and interest to justify their appearance. The editor who is in this fortunate position of having a plenitude of material from which to select only, therefore, incidentally influences the trend of opinion of the contents of his paper, as to a large extent the subjects to be dealt with are those which have in the course of their own experience come to the minds of his contributors as of topical interest for discussion. Generally speaking, if one worker has come up against a problem, or had a particular subject forced on his notice, sufficiently to inspire him to set down his ideas on it, it is reasonably certain that the same stage has been reached by other workers in the same field.