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. ior> | 106 Index Larmor : action of magnetism on light, 112. Lens : formation of image by, 26. Leverrier: discovery of Uranus, 24. Linear measurements : attainable accuracy in, 25. Lorentz: action of magnetism on light, 112; aberration, 156. Magnetism : action on light, 107. Magnification : produced by lens, 27 ; loss of light in, 27; of fringes by interferometer, 32. Manometric capsule, 10. Mars, 128. Maxwell : aberration, 156. Mercury : analysis of radiations of, 80. Meter : manufacture of, 87; value in waves of cadmium light, 104. Microscope : efficiency of, 25; limit of resolution of, 30. Molecules: complexity of, shown by spectrum, 82. Morley : measurement of coefficient of expansion, 55. Moving media: effect on velocity of light, 151. Music : color, 2. Newton: corpuscular theory, 45; spectrum, 60. Objective: relation to size of diffraction pattern, 30. Pendulum : motion of, 6; as standard of length, 86. Period, 6. Phase : defined, 7; loss of by reflection, 16. Poisson: diffraction, 21. Polarization, 110. Quincke: interference of sound, 9. Rayleigh : diffraction of sound, 21; discovery of Argon, 24. Reflection : change of phase on, 16. Refraction : comparison of theories of, 47; index of, 50; measurement of index of, 51. Resolution: of telescope, 29,130; of microscope, 30; of spectroscope, 62; of grating, 121; of echelon, 125. Revolving mirror, 48. Ripples: interference of on surface of mercury, 11. Rogers: measurement of coefficient of expansion, 55. Ruskin, 1. Saturn, 128. Screw : testing with interferometer, 57. Sensitive flame, 19. Simple harmonic motion, 6; curve, 7. Sine curve, 7. Slit: diffraction produced by, 22. Soap film : colors of, 14. Sodium : spectrum of, 61: distance between lines a standard of measurement, 62; distance between lines of, 66; analysis of radiations of, 78; action of magnetism on radiations of, 107. Sound waves : interference of, 9; diffraction of, 19; shadow produced by, 20. Source of light : distribution of, 75. Spectral lines: structure of, 62; analysis of with interferometer, 73. Spectrum, 60; of sodium, 61, 78; of hydrogen, 78; of thallium, 79; of mercury, 80; of cadmium, 81; order of, 121. Standards of length, 86. Star discs : size of, 143. Struve: Jupiter’s satellites, 142. Telescope: efficiency of, 25; limit of resolution of, 29,130. Thallium : analysis of radiations of, 79. Tuning-forks : beats formed by, 12. Undulatory theory, 44. Uranus: discovery of, 24. Vacuum tubes : as sources of light, 75. Velocity: of wave motion, 8, 146; of light, 146. Visibility : defined, 68; curves with the interferometer, 70; with the double slit, 139. Vortex theory, 161. Wavelength: definition of, 7; measurement of, 17; as standard of length, 84. Wave motion, 3; kinetic model of, 4; Kelvin’s dynamic model of, 5; propagation of, 7. Wheatstone: velocity of light, 48. Young : interference, 22. Zeeman : action of magnetism on light x 107. Zinc : spectrum of, 62. |