How long can men thrive between walls of brick, walking on asphalt pavements, breathing the fumes of coal and of oil, growing, working, dying, with hardly a thought of wind, and sky, and fields of grain, seeing only machine-made beauty, the mineral-like quality of life?

Lindbergh’s question contrasts industrial modernity with the sustaining presence of the natural world. The imagery—brick walls, asphalt, coal and oil fumes—evokes the enclosed, mechanized city as an environment that can keep bodies alive while starving the senses and spirit. By asking “How long,” he frames urban-industrial life as potentially unsustainable, not only ecologically but psychologically and culturally: people may “grow, work, [and] die” without ever encountering wind, sky, or living landscapes. The phrase “machine-made beauty” suggests a counterfeit aesthetic replacing organic complexity, while “mineral-like quality of life” implies a hardening or deadening of human experience into something inert.