98.

Phonograph, 310;
governor, 311;
recorder, 312, 313;
records, making of, 319;
reproducer, 315;
tracings on record of, 317.

Pianoforte, 277;
sounding-board, 280;
striking mechanism, 281;
strings, 281.

Piccolo, 308.

Pipes, closed, 289;
flue, 301;
open, 292;
organ, 295;
reed, 301, 302;
tuning, 302.

Piston valve, 67.

Pneumatic tyres, 341.

Poldhu, signalling station at, 138.

Points, railway, 208, 210;
and signals in combination, 211.

Poles of a magnet, 115.

Popoff, Professor A., 138, 145.

Power, transmission of, 175.

Preece, Sir William, 145.

Primary winding of induction coil, 122.

Pump, air, 340;
bucket, 352, 353;
force, 354;
most marvellous, 355;
Westinghouse air, 199.


Railway brakes, 187;
signalling, 200.

Rays, converging and diverging, 256;
heat, concentrated by lens, 232;
light, 232, 235, 236, 237.

Records, master, 319, 320.

Reciprocation, 51.

Reed, human, 306;
pipes, 301, 302.

Reflecting telescope, 260.

Relays, telegraphic, 133, 141.

Retina, 247.

Retorts, 395.

Reversing gear, 62;
Allan, 65;
Gooch, 65;
radial, 66.

Rocking bar mechanism for watches, 425.

Rods of Corti, 274.

Ruhmkorff coil, 121, 122.


Safety-valve, 32, 33, 391.

Sand-glasses, 411.

Scissors, action of, 450.

Secondary winding of induction coil, 122.

Series arrangement of electric lamps, 183.

Series winding of dynamo, 173.

Shunt wound dynamo, 173.

Sight, long and short, 250.

Signalling, automatic, 228;
electric, 225;
pneumatic, 225;
power, 225.

Signal levers, 206.

Signals, interlocking of, 204;
position of, 202;
railway, 200;
single line, 215.

Silencer on motor cars, 109.

Siphon, 351.

Slide-valve, 49, 50, 51;
setting of, 53.

Sliders, 297.

Sound, nature of, 270;
board of organ, 296;
board of piano, 280.

Spagnoletti disc instrument, 212.

Sparking-plug, 102.

Spectacles, use of, 249.

Spectrum, colours of, 230.

Speed governors, 67, 68, 69;
Hartwell, 70;
marine, 71.

Speed of motor cars, 110.

Spot, blind, in eye, 251;
yellow, in eye, 251.

Spring balance for watches, 419;
compensating, 423, 424.

Stapes, 272.

Steam, what it is, 13;
energy of, 14;
engines, 44;
engines, reciprocating, 45;
expansive working of, 59, 81;
gauge, 36;
gauge, principle of, 37;
turbine, 74;
turbine, De Laval, 76, 77;
turbine, Hero's, 74;
turbine, Parsons, 79, 80;
volume of, as compared with water, 15.

Stephenson, George, 63, 375.

Stop, in lens, 244;
iris, 249;
use of, 244.

Sun-dial of Ahaz, 410.

Syntonic transmission of wireless messages, 143.


Talking-machines, 310.

Tapper in wireless telegraphy receiver, 141.

Tappet arm, 205.

Telegraph, electric, 127;
insulator, 133;
needle, 128;
recording, 133;
sounder, 132.

Telegraphy, high-speed, 135;
wireless, 137.

Telephone, 147;
Bell, 148;
circuit, double-line, 155;
circuit, general arrangement, 152, 153;
exchange, 154, 155.

Telephony, submarine, 157.

Telescope, 257;
Galilean, 259;
prismatic, 260;
reflecting, 260;
terrestrial, 259.

Threshing-machine, 447, 448.

Thurston, Professor, 31.

Tides, 452;
high, 453;
neap and spring, 455.

Timbre, 285.

Tompion, Thomas, 412.

Torricelli, 325.

Trachea, 306.

Train staff signalling, 216;
single, 216;
and ticket, 217;
electric, 218.

Transformation of current, 124, 176.

Transmission of power, 174, 175.

Transmitter, Edison telephone, 150;
granular carbon, 150, 151.

Triple-valve, 196.

Trolley arm, 176.

Turbines, steam, 74.

Turbinia, the, 79.

Tympanum, 137, 271, 272.


Universal joint, 93.


Vacuum brake, 189, 190, 191.

Vacuum chamber of aneroid barometer, 330.

Valve, piston, 67;
safety, 32;
of internal-combustion engine, 89.

Valves of the heart, 357.

Veins, 358;
capillary, 358;
pulmonary, 361.

Ventral segments, 291.

Ventricles, 357.

Vibration of columns of air, 288, 289;
of rods, 287;
of strings, 278;
of strings, conditions regulating, 278.

Viper, the, 86.

Virag, Pollak—high-speed telegraphy, 136.

Vitreous humour, 246.

Voltage, 121, 161.

Vowel sounds, 308.


Wasborough, Matthew, 51.

Watches, first, 412.

Water cock, 365;
engines, 375;
gauge, 35, 36;
jacket, 19, 95;
meter, 368;
supply, 371;
turbines, 174, 376;
wheels, 375.

Watt, James, 51, 69, 375.

Welsbach incandescent mantle, 407.

Westinghouse air-brake, 194, 195, 197;
George, 194.

Wheatstone needle instrument, 128, 131;
automatic transmitter, 135.

Wind, why it blows, 323;
action of on kites, 345;
on sails, 346.

Windmills, 375.

Window, oval, in ear, 272;
round, in ear, 272.

Wireless telegraphy, 137;
advance of, 145;
receiver, 140, 141;
syntonic, 143;
transmitter, 138, 139.


Yale lock, 436, 437.

Yellow spot, in eye, 251.


Zech, Jacob, 414.

Zeiss field-glasses, 260.