"Carnegie Watched, Listened, Learned" from Scott's Process Innovations
(p. 65) Later in life, Scott would be better known for his political skills, but he was, like his mentor Thomson, a master of cost accounting. Together, the two men steadily cut unit costs and increased revenues by investing in capital improvements--new and larger locomotives, better braking systems, improved tracks, new bridges. Instead of running several smaller trains along the same route, they ran fewer but longer trains with larger locomotives and freight cars. To minimize delays--a major factor in escalating costs--they erected their own telegraph lines, built a second track and extended sidings alongside the first one, and kept roadways, tunnels, bridges, and crossings in good repair.
Carnegie watched, listened, learned. Nothing was lost on the young man. With an exceptional memory and a head for figures, he made the most of his apprenticeship and within a brief time was acting more as Scott's deputy than his assistant. Tom Scott had proven to be so good at his job that when Pennsylvania Railroad vice president William Foster died unexpectedly of an infected carbuncle, Scott was named his successor.
Nasaw, David. Andrew Carnegie. New York: Penguin Press, 2006.
(Note: the pagination of the hardback and paperback editions of Nasaw's book are the same.)