The theory and practice of illumination
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Thomas W. Rolph
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Article
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1909
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Elsevier Science
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English
⚖ 837 KB
IN any branch of engineering, practice usually precedes theory. As practice develops and becomes more wide-spread,its faults show themselves, and in the attempt to remedy these faults the theory is evolved. Theory reacts upon practice, improving it, and practice in turn reacts upon theory, causing a