This paper describes the tools and operations common in general engineering, steel making, oil refining, building and mining, and goes on to show that the names given them indicate a preoccupation with sexual thoughts on the part of those who use them. Advantage is taken of crude similarities between operations and bodily functions, shapes, and anatomical details. Thus parts which fit together are designated by their relative positions as male or female, a steel furnace is considered as though it were a parturient woman, and vulgar terms for virility, such as 'jack', 'ram', 'dog', or 'cock', abound.