An engineer can be a nation's most practical economist. This address shows how engineering choices shape costs, growth, and daily life. Drawing on centuries of technological progress, the talk explains how engineers apply science to improve health, energy, and industry while balancing investment, maintenance, and future change. It mixes historical insight with clear, real‑world examples to reveal the economic logic behind design decisions—from pipes and power to railways and illumination. Read to understand how engineering thinking connects private enterprise, public welfare, and lasting civilization. The speaker argues that durable, efficient systems depend on careful cost thinking, foresight, and a disciplined approach to depreciation and innovation. See how depreciation, maintenance, and future inventions influence today’s engineering choices. Explore practical examples, from water supply and ventilation to transportation and lighting. Learn why engineers balance capital costs with operating expenses to achieve lasting value. Understand how engineering advances broaden human well‑being and economic progress. Ideal for readers interested in the history of technology, engineering practice, and the economics that drive public and private progress.