A popular magazine article from Technical World (1911) on the new profession of illuminating engineering and the proper use of artificial light. It uses examples such as a Chicago theater rescued from failure by indirect lighting, show windows, libraries, drafting rooms and homes. It compares incandescent, tungsten, mercury vapor, Moore tube and Cooper-Hewitt lighting, and covers glare, shadows, color of light, fatigue and the lumen. Photographs include a silk ribbon loom in a Paterson, N.J. mill shot under ordinary lights and under Cooper-Hewitt light, and a well-lit cotton mill.