Encyclopædia. Encyclopædia Britannica 14th edition. 1954. 引文格式1维护：冗余文本 (link) Aside from providing an excellent summary of the Britannica's history and early spin-off products, this article also describes the life-cycle of a typical Britannica edition. A new edition typically begins with strong sales that gradually decay as the encyclopaedia becomes outdated. When work on a new edition is begun, word leaks out and sales of the old edition effectively stop, just at the time when the fiscal needs are greatest: a new editorial staff must be assembled, articles commissioned, etc. Elkan Harrison Powell（英语：Elkan Harrison Powell） identified this cyclic fluctuation of income as a key danger to the fiscal health of any encyclopaedia, one that he hoped to overcome with his innovative policy of continuous revision.
