Ключевые слова: 20s, 60s, apprentice, apprenticeship, engineer, engineering, equipment, factory, glasses, goggles, horizontal, industry, learning, machine, machinery, machinist, male, man, manufacturing, men, mill, milling, occupation, operating, operator, person, safety, side, sixties, skill, teaching, technology, together, trail, training, twenties, view, worker, working, workshop,