Behind Galileo's amazing discoveries with the telescope was a lens grinder, whose competence made the observations possible. This is a pattern that has repeated itself many times over, and only a few observational and experimental scientists have been able to function without the help of skilled craftsmen, their skills often promoting them into collaborators, acknowledged at the end of a paper rather than among the list of authors. As the industrial age progressed investigators found an ever-growing array of devices useful and even vital to their trade, such that with time the initiation of a new experimental study required an assortment of catalogues near the drawing boards of the designer. This dependence on the industrial base has in recent years even overtaken theory, where electronic computers have changed that pencil-and-paper field in a way that is revolutionary, to use correctly this overworked adjective. Those who are conversant with the various aspects of these new technologies are often more important to the DTM staff than many of their colleagues, and are easily overlooked in a history, which all too often rings with statements such as: “Caesar conquered Gaul.” But didn't he even have a cook with him? Craftsmen were indeed among the first persons mentioned in the early Year Books and thus were clearly appreciated.

As noted in the Preface, the number of persons who made active and important contributions to the Department's functions, both scientific and supporting, is so large as to make mention of more than a small fraction impossible in these pages, if the book is to be kept readable and of reasonable length.