Half of the eight contributions to this volume are philosophical: two papers on the relationship of the history of technology to general history; a discussion of what should be the engineer's concern with history; and musings on what it means to have knowledge of a subject, led up to by a discussion of documentary records of the history of technology. The other papers treat irrigation in India; Vitruvius' writings on elevated aqueducts; the development of fossil fuel technology and related pollution problems; and the evolution of an understanding of the calming effect that oil has on waves, i.e., pouring oil on troubled waters. See also 14-93 and 20-321. -- AATA