INDEX.
Aberration, 149.
Accuracy of measurement: value of increasing, 23: limit without lenses, 25; limit with lenses, 27; increase due to lenses, 30; increase due to interferometer, 36; of standards of length with grating, 85; of length of seconds pendulum, 86; of earth’s circumference, 87 ; of wave length with the interferometer, 98.
Air wedge: interference produced by, 15.
Amphipleuka pellucida : use as test of resolution, 30.
Amplitude, 6.
Analysis ; of periodic curves, 68; of the nature of a source of light, 76.
Analyzer ; harmonic, 68.
Arago : velocity of light, 48; interferometer, 51.
Beats; between tuning-forks, 12.
Black spot : on soap film, 53; thickness of, 54.
Boiling of star images, 129.
Bradley : aberration, 149.
Burnham: Jupiter’s satellites, 142.
Cadmium: analysis of radiations of, 81; red radiation as standard of length, 91; number of waves in meter, 98; action of magnetism on radiations of, 116.
Comets : resistance by ether to motion of, 45.
Corpuscular theory, 44.
Diffraction; of sound waves, 19; in telescope and microscope, 29; by rectangular opening, 32.
Diffraction pattern: due to circular opening, 29, 130; due to rectangular opening, 133; due to two slits, 134.
Double slit; use of in astronomical work, 134.
Earth: resistance by ether to motion of, 45,148; circumference of as standard of length, 87.
Echelon spectroscope, 122.
Efficiency: of microscope and telescope, 25.
Electrolysis, 113.
Electromagnetic nature of light, 160.
Engelmann: Jupiter’s satellites, 142.
Ether: properties of, 45, 146; vortex-theory of, 161.
Expansion: measurement of coefficient of, 5o.
Faraday: action of magnetism on light, 107.
Fievez: action of magnetism on light, 107.
Fitzgerald: action of magnetism on light, 112.
Fizeau: velocity of light, 48; in moving media, 152.
Foucault : velocity of light, 48.
Fraunhofer: lines in solar spectrum, 60.
Fresnel : measurement of index of refraction, 51; moving media, 152.
Fringes: , due to two openings, 33; breadth of, 34; use of in spectrum analysis, 64.
Gases : liquefaction of, 24.
Gould : standards of length, 84, 103.
Grating : diffraction, 23, 84, 119; efficiency of, 121.
Gravitation constant: measurement with interferometer, 56.
Gun sight : use in measuring angles, 25.
Harmonic motion, 6; analyzer, 68.
Hertz; oscillator, 160..
Hough: Jupiter’s satellites, 142.
Hydrogen : analysis of radiations of, 78.
Image: formation of, 26.
Interference: definition of, 8; of sound waves, 9; of mercury ripples, 11; of light in soap film, 12; of two trains of waves, 64.
Interferometer: definition of, 33, 36; description of, 40; application of to measure index of refraction, 51; to measure thickness of soap film, 53; to measure coefficient of expansion, 55; to measure gravitation constant, 56; to test screws, 57; to measure light waves, 58; to analyze spectral lines, 60, 73, 78; to determine standards of length, 89; to the Zeeman effect, 108, 114; to astronomical measurements, 127; to aberration, 157.
Intermediate standards of length, 93.
Iron: spectrum of, 62.
Johonnott: thickness of liquid films, ->4.
Jupiter, 128; size of satellites, 141.
Kelvin : dynamic model of wave motion, 5,16.
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