672 



INDEX 



PAGE 



Molecular free paths SSo 



, air molecules 563 



heats of adsorption 554 



liquefaction 554 



magnitudes 551 



number, Avogadro's, 6.064X10 23 mole- 1 . 104 

 in cm 3 , An, 0° C, 2.7osxio 19 . 107 

 Loschmidt's, 2.705 xio 19 cm -3 . 107 



organic cross-sections 551 



spectra: diatomic molecules, 



constants 51 2-5 1 3 



energy levels 51 2-5 1 3 



heats of dissociation 512-513 



rotational levels 51 2-5 1 3 



velocities 550 



weights of colloids 553 



Moments of inertia: earth 570 



formulae 72 



Month, definition 660 



sidereal, synodical 601 



Moon : albedo 607 



distance from earth 601 



history (tidal, etc.) 573 



magnitude, — 12.5 623 



tides 573-574 



Mountain, highest 569 



Movie-lights, characteristics 339 



Multiplicity, spectrum series 502, 503 



Musical instruments: loudness 194 



overtones 194 



partials 194 



peak power 194 



scales 192 



Nebulae: classification 639 



dark 639 



diffuse 639 



dimensions 640 



distance 641 



external galaxies 641 



extra-galactic 642 



galactic 639 



high velocities 641, 642 



Magellanic clouds 640 



magnitudes 641 



N. G. C. 6822, dimensions 640 



nongalactic 640 



planetary 639 



radial velocities 641 



velocities, high 641, 642 



radial 641 



Neon, standard wave lengths 349 



Nernst, thermomagnetic potential difference 482 



Neutralization, heats of 312 



Newtonian gravitation constant, 



6.664 x io _s dyne • cm 2 • g~ 2 75 



Nickel: Kerr's constants 383 



magnetic properties, 0°, 100° C 469 



mechanical properties 124 



resistance in magnetic field 384 



Nitrogen, compressibility 146 



gas thermometer 249 



Nitroso-dimethyl-aniline, refractive index 361 



Noises, loudness levels 193 



Novae 617, 635 



Nuclear charge, atomic 492 et seq. 



Nuclei, Aitken, atmospheric 597 



Number: atomic 483, 485 



Julian 601 



magnetic character, month and year 595 



stars 618 



first magnitude 619 



known within 5 parsecs 619 



sun-spot, yearly 610 



Nutation 601 



Observatories, magnetic: bibliography 589 



positions and magnetic ele- 

 ments 581 



Ocean: areas 569, 650-651 



basins 650-651 



chemical properties 652 



depths 569, 650-65 1 



gradients 650 



oceanography 569, 650 et seq. 



physical properties 651-652 



seismic waves 653 



swell 653 



Ocean: tides 573-574 



waves, pressure, dimensions 653 



wind waves 653 



Oersted liv 



Ohm, absolute xlvii, '77V 397! 660 



electric equivalents yy t 397 



Oils: compressibility, petroleum 155 



films, thickness 55 j 



thermal expansion, petroleum ,,'. 155 



viscosity : castor 206 



gasoline, kerosene 207 



Optical constants of metals 377-378 



pyrometry 248 



rotary power (I. C, T., 2, 153. 334; 7, 



353) 396 



rotation, magnetic 476-480 



thermometry 248 



Orbital velocity of earth 570 



Organ pipes, pitch 194 



Organic compounds: boiling points 256-258 



densities 256-258 



melting points 256-258 



molecules, cross-sections 551 



salts : solubilities 219 



Oscillation constants, wireless telegraphy 460 



times of wires, temperature variation... 137 



Overtones (sound) 193 



, musical instruments 194 



speech 195 



Oxides: brightness, incandescent 336 



emissivities (radiation) 320, 324 



tt, 3-14159265359 14, 660 



P limit, mechanical property no et seq. 



Packing fractions 484, 648 



Parallax, first magnitude stars 619 



large velocity stars 627 



lunar 601 



nearer stars 619 



small velocity stars 627 



solar 601 



vs. mean magnitude 624 



Paramagnetism 463, 474 



Parsec 601, 660 



Partials, musical instruments 194 



Particle, smallest visible 553 



Pauli-Sommerfeld theory (I. C. T., 6, 353) 



Peltier phenomenon 406-407 



pressure effect 407 



Pendulum, length of seconds 568 



Pentane candle 334, 660 



Period. Julian 601 



Periodic system : Hackh 486 



Mendeleeff 485 



Permalloy 472 



Permeability, magnetic xxxii, 559 



Persistence of vision 332 



Persistent spectrum lines 507 



arc 509 



spark 510 



Petroleum oils: compressibility 155 



thermal expansion 155 



Phenol-resinoid products: physical properties 655 



Phonetic power of conversation 195 



spoken vowels 195 



Phosphorescence, radium 321 



Phot 333 



Photoelectricity (I. C. T., 6, 67) 547. 548 



Photography: astrogamma 343 



definitions 343 



developer, pyrogallol 342 



development velocity constant 341 



Eberhard effect 345 



efficiency various illuminants 344 



fog 341 



gamma 341 



illuminants, efficiency of 344 



inertia 341 



intensification 341. 345 



latitude 341 



photometry 345 



plates 342 



spectrum sensitiveness 



(films) 343, 344 



pyrogallol development 342 



reflection of light by plates 343 



