Radiation, Light and Illumination is a sequence of engineering lectures delivered at Union College. It treats radiation, light, electric waves, photometry, arc lamps, illumination, and visual physiology as one engineering field.
This makes it a strong first source for the archive: it contains explicit radiation and ether language, a frequency/wavelength scale connecting electric waves and light, and later chapters that force a careful distinction between physical power and human perception.
The book should not be read as an isolated lighting manual. It begins with radiation as a general physical phenomenon, then narrows toward light, vision, photometry, lamps, and practical illumination. That arc is valuable because it shows Steinmetz refusing to collapse different layers of reality into one word: radiation is not automatically heat, light is not automatically illumination, physical energy is not automatically human visual effect, and measurement is not automatically experience.
For this archive, that means each lecture needs two kinds of decoding. The first is physical and mathematical: waves, frequency, wavelength, emission, absorption, reflection, refraction, flux, intensity, and distribution. The second is conceptual and historical: how early electrical engineering organized radiation, light, high-frequency electrical phenomena, and practical lighting before later textbook language standardized the vocabulary.
Promote first because it anchors the entire book and gives the archive its first example of Steinmetz separating an energy process from the effect produced after absorption.
Electric Waves
Promote first because the opening lecture connects ordinary AC fields, Hertzian waves, wireless waves, visible light, ultraviolet, and X-rays through frequency and wavelength.
Illumination
Promote first because the later lectures show how physical radiation becomes practical lighting only after geometry, source distribution, measurement, and visual response are considered.
Scan crop from printed page 17, preserving Steinmetz’s tabular frequency and wavelength map.
Original Fig. 14 crop
Scan crop from printed page 18, now linked to the diagram archive as the first original Steinmetz figure asset.
Original Fig. 15 crop
Scan crop from printed page 22, preserving the wavefront geometry behind the refraction derivation.
Spectrum guide
Lecture I reading aid for frequency, wavelength, and the continuity of electric waves and light.
Illumination guide
Later-lecture reading aid for flux, distance, receiving area, and useful illumination.
Quality Note
The current source text is OCR-derived. It is good enough for discovery, but equations, page references, Greek letters, figure captions, and exact quotations must be checked against the scan before canonical publication.
Generated source dashboard: this section joins the source overview to the book coverage atlas, source text reader, chapter workbench, visual maps, and formula maps. Counts are candidate research aids until scan verification promotes them.
Radiation, Light and Illumination currently contributes 13 processed sections and 86,387 candidate OCR/PDF-text words to the archive. Its strongest tracked evidence clusters are Radiation / light, Magnetism, Waves / transmission lines.
This is a routing judgment based on processed metadata, not a final historical claim. The strongest next move for any exact quotation, equation, or diagram is still to open the source scan and check the page image.
