Early 20th-century American technical writing textbooks were addressed primarily to students and practitioners ef engineering. The article argues that 12 important textbooks datingfrom 1911-1930 somewhat paradoxically conflate three different traditions eflanguage use prevalent in America at the time. This conflation occurs because engineers in their dual role as applied scientists and progressivist managers were extraordinarily sensitive to language use. In turn, broader social and intellectual currents in America are used to explain engineers' linguistic concerns, which the textbooks, based on engineering practice, mirror. ALTHOUGH I HAVE WORKED as a technical writer and editor, and although I have taught technical editing and business communication, my primary academic training has been in languages and linguistics. Currently I teach courses on general linguistics and on the history ofEnglish. My scholarly publications focus mainly on how English is used in professional (business, scientific, and technical) documents and on how practitioners, teachers, and theorists have conceptualized the role of language in such texts. This autobiographical information has been included to clarify my approach to this paper, which presents a preliminary account of how certain ideas about language prevalent in post-helium America were combined and codified in early engineering writing textbooks. These textbooks, which primarily address engineering students and practitioners (Connors, 1982; Hagge, 1995), reflect the preoccupations of the contemporaneous engineering profession 1 This article is a revision of a paper presented as Invited Speaker, Canadian Association of Teachers of Technical Writing, Learned Societies Conference/Congres des societes savantes, Calgary, June 4, 1994. Initial research was done during an Iowa State University On-Campus Sabbatical Semester for Study in a Second Discipline, Spring, 1994.