ABSTRACT
A good demonstration lecture is a dramatic performance and there is no doubt that the lecturer must be at least a performer, if not an actor, in order to put over a demonstration lecture effectively. This may be one of the factors that leads some scientists to feel that there is something not quite respectable about such an activity; thankfully this attitude is beginning to be a thing of the past. Later in the book I shall from time to time draw parallels between a demonstration and a play; the same principles of variation in tension, of careful preparation and rehearsal, of clear diction and easily visible properties and actions all apply.
