INDEX 



827 



Waves at sea — continued 

 sea, 778 

 surf, 778 

 swell, 778 

 height 



vs. distance from source, 772 

 vs. wind, 778 

 velocity: deep water, 777 

 shallow water, 777 

 Weighing: effect of the air, 69 



reduction to vacuo, 69 

 Weight, calculated, various bodies, 27 

 Wet-dry bulb temperature and humidity, 



602 

 Wien displacement constant, 80 

 Wien displacement law, 80 

 Wire (see also Copper) : 



aluminum, properties of, 415 



mass resistivity, 404 

 copper, properties of, 406 

 annealed, 408 



characteristics of, 408 

 electric, 408 

 carrying capacity (safe), 416 

 mass resistivity, 404 

 resistance, computing, 417 

 resistance to standard temperature, 407 

 temperature coefficient of resistance, 

 404 

 electrical and mechanical characteristics, 



408 

 gages, comparison of, 405 

 high-frequency resistance, 417 

 calculations, 417, 419 

 of conductors, 417, 419 

 maximum diameter for high-frequency re- 

 sistance ratio of 1.01, 420 

 ratio of alternating to direct current 



resistance, 419 

 rope, 216 

 steel, 216 



tables, comparison (gages), 405 

 for computing resistances, 416 

 tubular conductors, resistance, 418 

 Wolf's sunspot number, 727 

 Wolfram (see Tungsten) 



X-rays, 654, 692 

 absorption, 693 



coefficients, 693, 694 



formulas, 693 

 constants, 693 

 critical, 692 

 K series, 696, 698 

 L series, 696, 699 

 M series, 696 

 mass absorption, 704 

 calculated, 704 



elements, 695, 697 

 materials, 696 

 formula, 693 

 wavelengths, critical, 692 

 elements, 697 

 voltage, 692 

 characteristics, intensity, 692, 693 

 wavelength, 692, 693 



X-rays — continued 

 dosage units, 694 



lead thickness to reduce, 695 

 rate, 695 

 emission, characteristic, materials, 696 



K series, 696 

 energy, radiated, 692 

 filters for obtaining monochromatic, 696 

 fluorescence, excited by, 693 

 materials, 693 

 wavelength, 693 

 generated, 692 

 ionization, 693 



gas and vapors, 693 

 mass absorption, 694 



formula, 694 

 nature, 692 

 production, 692 

 quantity, 692 

 protection against, 693, 694, 695 

 concrete, 694 

 distance vs. voltage, 695 

 lead, 695 



materials vs., 694 



minimum thickness vs. intensity, 693 

 requirement vs. voltage, 693, 695 

 for 400 kv pulsating, 695 

 for 1000 kv pulsating, 696 

 for 10 ma pulsating, 695 

 thickness vs. voltage, 695 

 quantity, tungsten target, 692 

 safe rating of tubes, 698 

 spectrum, 692 



limit, 692 

 terms, various elements, 698 

 tubes, safe operating, 698 

 types, 692 



characteristics, 692 

 continuous spectrum, 699 

 wavelength limit, 692 

 wavelength, 692 

 characteristic, 692 

 critical absorption for elements, 701 

 fluorescent, 693 

 K series, elements, 696, 697 

 L series, elements, 699 

 M series (72Ta to 92 U), 700 

 tungsten L series, 698 

 various elements, 700 

 various transitions, 697 

 voltage and, 692 

 X-unit, 509 



Year: anomalistic, 731 



light, 730 



sidereal, 731 



tropical, 731 

 Yearly means: magnetic characteristics, 

 481-492 



solar constant, 719 



sunspots, 727 



temperature, 726 

 Yield point (materials), 188 

 Young's modulus, 7, 188 



Zeeman effect, 50 



Zero, absolute, 9, 47, 73 



Zinc, physical properties, 225 



