Skip to content

Lecture 11: Light Intensity And Illumination

Research workbench, not a finished commentary page.

This page is generated from processed source text and candidate catalogs. It exists to help researchers decide what to verify, promote, and deeply decode next.

FieldValue
SourceRadiation, Light and Illumination
Year1909
Section IDradiation-light-and-illumination-lecture-11
Locationlines 12574-16484
Statuscandidate
Word Count4890
Equation Candidates In Section0
Figure Candidates In Section16
Quote Candidates In Section0
LECTURE XI. LIGHT INTENSITY AND ILLUMINATION. A. INTENSITY CURVES FOR UNIFORM ILLUMINATION. 102. The distribution of the light flux in space, and thus the illumination, depends on the location of the light sources, and on their distribution curves. The character of the required illumi- nation depends on the purpose for which it is used: a general illumination of low and approximately uniform intensity for street lighting; a general illumination of uniform high intensity in meeting rooms, etc.; a local illumination of fairly high intensity at the reading-table, work bench, etc. ; or combinations thereof, as, in domestic lighting, a general illumination of moderate inten- sity, combined with a local illumination of high intensity. Even the local illumination, however, within the illuminated area usually should be as uniform as possible, and the study of the requirements
LECTURE XI. LIGHT INTENSITY AND ILLUMINATION. A. INTENSITY CURVES FOR UNIFORM ILLUMINATION. 102. The distribution of the light flux in space, and thus the illumination, depends on the location of the light sources, and on their distribution curves. The character of the required illumi- na ...
LECTURE XI. LIGHT INTENSITY AND ILLUMINATION. A. INTENSITY CURVES FOR UNIFORM ILLUMINATION. 102. The distribution of the light flux in space, and thus the illumination, depends on the location of the light sources, and on their distribution curves. The character of the required illumi- nation depends on the purpose for which it is used: a general illumination of low and approximately uniform intensity fo ...
... 7, of the beam reaching this point, and inversely proportional to the square of the distance I of the point from the effective center of the light source : If the beam of light makes the angle <f> with the vertical direction, the illumination, i, is thus in the direction <j>, the horizontal illumination, that is, the illumination of a horizontal plane (as the surface of a table), is , 7cos< , ih = i cos 0 = 226 LIGHT INTENSITY AND ILLUMINATION. 227 and the vertical illumination, that is, the illumination of a vertical plane (as the sid ...
Concept CandidateHits In SectionStatus
Illumination142seeded
Light140seeded
Radiation14seeded
Brilliancy1seeded
Term CandidateHits In SectionStatus
candle-power16seeded
brilliancy1seeded
flux of light1seeded
Candidate IDOCR / PDF-Text CandidateSource Location
No chapter-local candidates yet--
Candidate IDOCR / PDF-Text CandidateSource Location
radiation-light-and-illumination-fig-095a horizontal plane P, then, for a point A at the horizontal dis- FIG. 95. tance lh from the lamp, L (that is, the distance lh from the pointline 12627
radiation-light-and-illumination-fig-096230 RADIATION, LIGHT, AND ILLUMINATION. FIG. 96. FIG. 97,line 12973
radiation-light-and-illumination-fig-098side illumination, and are rounded off where the branches join. FIG. 98. Fig. 99 gives the intensity curves for the same angles, w = 30,line 13427
radiation-light-and-illumination-fig-09945, 60, and 75 deg., for uniform illumination only in the hori- FIG. 99. zontal plane beneath the lamp, but no illumination beyondline 13434
radiation-light-and-illumination-fig-100candle power: FIG. 100. I. The direct-current enclosed carbon arc, with clear innerline 14004
radiation-light-and-illumination-fig-10108 0,4 06 08 10 12 It 16 18 20 22 24 26 28 FIG. 101. curve of the character discussed in Fig. 92. III. The magnetiteline 14030
radiation-light-and-illumination-fig-102105. With lamps placed at equal distances 4o, and equal FIG. 102. heights lv, as shown diagrammatically in Fig. 102, the illumina- tion of any point A of the street surface is d…line 14060
radiation-light-and-illumination-fig-107lamp. Such a distribution curve can, for instance, be produced FIG. 107. by a spiral filament F (Fig. 108) located eccentric in a spher- ical globe G, of which the upper part is…line 14597
Candidate IDCandidate PassageSource Location
No chapter-local candidates yet--
  • Radiation / light: Compare the chapter’s radiation vocabulary with modern electromagnetic radiation, spectral frequency, wavelength, absorption, and illumination engineering.
  • Magnetism: Track flux, reluctance, permeability, magnetizing force, and loss language against modern magnetic-circuit terminology.
  • Complex quantities: Track how Steinmetz preserves geometric rotation and quadrature while translating the same operation into symbolic form.
  • Radiation / light: Radiation and wave language can invite ether-field comparison, but source wording, modern radiation theory, and speculative synthesis must stay separated.
  • Magnetism: Centrifugal/divergent magnetic-field readings are interpretive overlays, not automatic historical claims.
  1. Open the full source text and the scan or raw PDF.
  2. Verify the chapter boundary and surrounding context.
  3. Promote exact quotations only after checking the source image.
  4. Move mathematical candidates into canonical equation pages only after formula typography is corrected.
  5. Move diagram candidates into the diagram archive only after image extraction, crop verification, and manifest creation.
  6. Keep Steinmetz wording, modern translation, and ether-field interpretation in separate labeled layers.