None
On working the key, sparks pass between h and 6, affecting the antennae. Ether waves fly through space and are caught by the antennae A^ of the receiving station 2. The disturbance sends a momentary current through the primary Pg of the in- duction coil. Its secondary S2 then sends a current through Fig. 555.— WiBEiiEss Telegraphy Connections. the coherer c. This reduces the resistance of the coherer, and a current goes through it due to the battery B2 and through the relay magnet R, operating a Morse receiver on local circuit. There is a hammer which actuated by an electric magnet and make and break constantly taps the coherer, so that the coherer only retains its conductivity while acted on by ether waves. The instant they cease, the tapping restores its resist- ance. Long and short signals for the Morse code are sent by holding down the key K at the transmitting station for long or short periods. They are received by the receiving station and printed on a tape. >'' WIRELESS TELEGRAPHY. 735 Antennae and Connections. — Wires as nearly vertical as the requirements of suspension apparatus permit are used both for transmitting and receiving. The following may be given as a ty- pical example of the installation of such wires: Four iron lattice masts, each about 220 feet high, have their upper ends con- nected by horizontal wires, whence a quantity of small copper wires lead to the center of the system on the ground. Horizontal wires are without effect. The copper wires represent in appear- ance a sort of funnel. Such stations have been established on Cape Cod, U. S. A., and elsewhere on the coast. There is noth- ing final about this arrangement. At Poldhu, England, twenty masts are arranged in a circle to sustain the wires. Four hun- dred bare copper wires, each wire 200 feet long, are used. Fig. 556.— Marconi's Coherer. The wires are all connected at their lower ends to one terminal of a coil of a special induction coil. The other terminal of the coil is connected to the earth. From the secondary terminals of the coil wires are taken to condensers, whose other terminals are connected to the secondary of an induction coil. A con- denser is placed in this circuit, and across it and in parallel with the secondary coils is a spark gap connection. This gen- erally carries a pair of balls. The primary of the last-named induction coil receives current from a dynamo or storage bat- tery, and current is given or taken off by a sounding key. For ships two antenna are used. Near the mast top a yard about 30 feet long is slung, and from its ends two copper wire ropes about y^ inch in diameter are led down to the receiving and transmitting apparatus. Similar antennse are used for short- distance land stations. 736 ELECTRICIANS' HANDY BOOK. Marconi's Coherers. — ^Marconi's coherer, shown in Fig. 556, is a tube 1% inches long and 1/12 inch internal diameter. A chamber is made in the center by introducing two silver plugs with their ends 1/30 inch^ apart. A mixture of 90 per cent nickel filings and 10 per cent silver filings is contained in this space with a minute quantity of mercury. Hysteresis and Other Receivers. — The coherer used as a re- ceiver operates a relay circuit, and prints the message on a tape in Morse characters or their equivalent. This has the advan- tage of giving a fixed record. There are a number of receivers which do not give a record, some of which are based on magnetic lag. The hysteresis of iron is modified by ether waves impinging on it. In one of Marconi's receivers an endless iron wire is stretched around two pulleys, and passes through the core or axis of a double coil of insulated wire. The arrangement represents ^n induction coil with moving core. The primary receives the Impulses from the receiving antennae as already described. The secondary connects with a telephone receiver. The impulses modi- fy the hysteresis of the moving core, and sound is produced in the telephone. In another construction the core of the induction coil is fixed, and an electro-magnet rotates in front of it. The ether waves modify the hysteresis as in the case just cited, and the message is received by a telephone. There are a number of other constructions of receiving instru- ments in which a telephone is used as a receiver, the great sen- sitiveness of the telephone receiver causing them to be operative. The action of the ether waves on these classes of instruments is so slight that the instruments can only be used with a telephone receiver, and cannot actuate a printing recorder. On the other hand, the acoustic instruments are faster, other things being equal. INDEX. Access of Air 439 Accidents to Motors 415 Acid Depolarizers, Sulpliuric and jSitric 110 Acid Storage Batteries, Zinc. . 140 Action of a Circuit 66 Action of Arc Lamp on Con- stant-Potential Circuit 553 Action of a Storage Battery. 125 Action of Conductor 51 Action of Current on the jNIag- net 202 Action of Currents, Mutual . . . 199 Action of Drum Armature .... 233 Action of Inclosed-Arc 546 Action of Magnet Poles on Each Other 195 Adjusting Lamps 559 Adjusting Weight 552 Adjustment, Clutch Stop 560 Air-Blast Cooling 386 Air Blast, Effect of 538 Air Gap and Sparking 310 Air Pump, The Mercury 528 Air Switches 447 Air-Vane Damping 461 Alarm, Ground 457 Alternating-Current Arc 544 Alternating - Current Arc Lamps, Distribution of Light of 544 Alternating - Current Arc Lamps. Efficiency of 545 Alternating-Current Arc, Pow- er-Factor in 544 Alternating-Current Armature Winding. Principle of 350 Alternating- Current Circuit, Counter and Forward E.M.F. in 334 Alternating - Current Circuit, E.M.F. in 333 Alternating Current, Direct Current from 390 Alternating Current Distribu- tion 504 Alternating-Current Dynamo, Elementary Idea of 219 Alternating Current, Genera- tion of 348 Alternating-Current Ground In- dicator 456 ^Alternating-Current Lightning Arrester, Low-Equivalent. . . 521 Alternating-Current Potential Regulator 454 Alternating Current, Y. Connec- tions for 506 Alternating E.M.F 316 AlternatiPg E.M.F, and Cur- rent, Cause of Form of 319 Alternating E.M.F. and Cur- rent Curves 320 Alternating E.M.F. and Cur- rent, F'orm of 318 Alternating E.M.F. and Cur- rent, Production of 318 Alternating Quantities, Multi- plication of 344 Alternating Quantities, Sum- mation of 342 Alternator Brushes 435 Alternator, Inductor 356 Alternators, Field Magnets of 436 Alternators in Step 405 Alternators, Trouble in Rotors of 435 Alternator Winding, Six-Wire Connection of Three-Phase. 359 Aluminium Negative Plate.... 101 Amalgamation of Primary Bat- tery 96 American Storage Battery. . . . 134 American Wire Gauge 85 Ammeters 467 Ammeter, Shunted 469 Ammeter, Total-Current Sole- noid 467 Ammeter, Transformer 470 Ammonium-Chloride Batteries. 119 Ampere, Analogy for the 53 Amperes and Coulombs, Cur- rent 52 Ampere's Rule 203 Ampere's Paile Adapted to In- duction 213 Ampere's Theory of Magnetism 200 Ampere's Theory of Terrestrial Magnetism 201 Ampere Turns 176 Ampere Turns and Lines of Force, Relation between.... 183 Analogies of Drop of Poten- tial 60 Analogy for the Ampere 53 Angular Measurement 32 Annealing 181 Annunciator Lamp. Telephone. 709 Annunciator, The Mechanical. 708 Annular Chambered Magnet. . . 191 Anodes 660 Anode and Cathode, Position of 670 Anten le and Connections.... 735 Anti-Pci-allel Systems 488 Apparanjs, Large Plating. . . . 661 Appara<-us, "Photometer 567 Appa^ is. Receiving, Tele- phone 733 (37 738 ELECTRICIANS' HANDY BOOK. Apparatus, Simple Plating. . . . 661 Apparatus, Transmitting, Tele- phone 733 Appliances and Generators in Circuits 65 Appliances, Circuits without. . 64 Application of Circular Mil System 84 Application of Lenz's Law... 214 Arc, Alternating-Current 544 Arc and Incandescent Lamp Circuits 472 Arc Blowpipe, The Electric... 727 Arc. The Direct-Current Open. 540 Arc, Direct Heating by the Electric 727 Arc, Distribution of Light in Direct-Current Open 541 Arc, Heat of 536 Arc, Hissing 543 Arc Lamp, Direct Photometer- ing of 572 Arc Lamps, Features of Series or Constant-Current System for 475 Arc Lamp on Constant-Poten- tial Circuit, Action of 553 Arc Lamp, Photometry of . . . . 576 Arc Lamp, Resistance Coil in. 553 Arc Lamps, Commercial Rating of 542 Arc Lamps, Constant-Current or Series 551 Arc Lamps, Constant-Potential 555 Arc Lamps, Distribution of Light of Alternating-Current 544 Arc Lamps, Efficiency of Alter- nating-Current 545 Arc Lamps, Noise in 545 Arc, Length of 545 Arc Length, Voltage Drop and 538 Arc Light, Candle-Power in, Watts per 579 Arc Light Carbons 539 Arc Light, Efficiency of 537 Are Light. Quality of -. . . 580 Arc Lights, Distribution of Light from 582 Arc, Power Consumed in 538 Arc, Power-Factor in Alternat- ing-Current 544 Arc Proper, Ligbt Given by. . 543 Arc Proper, Resistance of . . . . 537 Arc, Striking the 535 Arc, The Voltaic 535 Arcs, Resistance of Longer... 543 Arcs, Resistance of Short.... 543 Area of a Circular Mil, Exam- ples of 84 Arithmetic and Mathematics. 17-40 Armature, Action of Drum... 233 Armature and Core 221 Armature, Balancing of 428 Armature out of Center 429 Armature, Centering of Armature, Closed-Coil Direct- Current Armature, Commutator Connec- tions of Ring Armature Connections, Drum. Armature Core, Action of Field Poles on Armature Core, Increasing B.M.F. by Adding Armature Cores, Eddy Cur- rents in Armature, Current in Ring. .. Armature, Disk Armature, The Drum Armature, End Leakage of Lines of Force in Armature, Mounting of Ring.. Armature, Multipolar Ring. .. Armature, Open-Wound Four- Part Ring Armature, The Pacinotti Armature, Pole Single-Phase .. Armature Polarity Due to Windings Armature Reaction Diagrams. Armature in Rotary Field.... Armature Rotation, Reversal of Armature Running Armature Shaft, End Motion in Armature, Short Circuits in .. Armature, Single-Phase Armature, Sixteen-Conductor Bipolar Armature, Armature, Armature Squirrel Cage Spindle or H Winding, General Formulas for Drum Armature Winding, Nomencla- ture for Drum Armature Winding, Principle of Alternating-Current .... Armature Windings, Break in. Armature Windings. Drum . .. Armature Windings and Frame, Short Circuits between Armature, Winding a Drum .. Armature Winding, Simple Sys- em of. Armature Windings, Laying out Drum Armatures, Cores of Ring. . .. Armatures, Modern Types of Closed-Coil Armatures, Open Coil.. Armatures, Pole Armatures, Various Armatures ■with F'ormed Coil, Winding. Arrangements of Batterips. . .. Arrester, Comb or Saw-Tooth, Lightnina- Arrester, Discriminating Light- ning . , 428 223 227 350 265 221 271 229 303 281 272 230 231 230 225 354 265 266 364 404 428 423 423 348 035 .367 000 246 246 350 422 233 435 241 234 243 228 226 222 301 193 » 301 122 518 519 INDEX. 739 Arrester, Double-Pole Light- ning 522 Arrester, Liglitning 591 Arrester, Low-Equivalent Alter- nating-Current Lightning... 521 Arrester. Magnetic Blow-Out, Lightning 518 Arrester, Non-Arcing Metal, Lightning 510 Arrester, Tank Lightning 522 Arrester, Westinghouse Light- ning 521 Arrival Curve 54 Astatic Galvanometer 605 Atomic Weights and Chemical Equivalents 89 Attraction and Repulsion of Magnetic Poles 202 Automatic Cut-Out 150 Automatic Regulation of Volt- age ^. 492 Auto-Transformer, The 381 Auxiliary Feeder Connections. 495 Average Values 327 S and E Curves 178 B and H Curves, Interpreta- tion of 179 B and H Synonyms for 178 Backing Up Deposits 675 Ballistic Calculation 614 Ballistic Galvanometer, The.. 610 Ballistic Measurement 613 Bar, Calculating Scale of Pho- tometer 568 Bar Photometer 563 Bath, Placing Molds in 674 Baths, Temperature of Plating 671 Battery, Action of a Storage. 125 Battery, Amalgamation of Primary 96 Battery. American Storage. 134 Battery, Baudet Siphon 107 Battery, Bunsen's 103 Battery, Camacho Cascade... 107 Battery Cell. The Primary... 93 Battery Cells, Insulation of Storage 161 Battery Cells, Storage 161 Battery, The Charge of Stor- age 145 Battery, Charging Storage.... 166 Battery, Chloride 136 Battery Connections, Booster and Storage 410 Battery Connections, Making Storage 161 Battery, Crompton-Howell. 135 Battery, The Daniell Ill Battery, Depolarizing Mixtures in Poggendoi-ff 109 Battery, Determination of Dis- charge of Storage 145 Battery, E'dison's Storage 140 Battery, End Cells of Storage 164 Battery, E.P.S 135 Battery Equalizer in Three- Wire System, Storage 501 Battery, Exciting Solutions in PoggendorfiE 109 Battery, Exhaustion of Pri- mary 96 Battery, Faure's 130 Battery, The Faure-Sellon- Volckmar 131 Battery, Floating Storage. 166, 410 Battery, Fuller's Mercury-Bi- chromate 106 Battery, Function of a Storage 128 Battery, Gibhs' 105 Battery, Gould Storage 132 Battery, Gravity 114 Battery, Grenet's 108 Battery, Grove's 102 Battery, Grove's Gas 126 Battery, Helios-Upton 133 Battery, Local Action of Pri- mary 96 Battery, Meidinger's 114 Battery, Modifications of Bun- sen's 104 Battery, Modifications of Dan- iell's 112 Battery, Modifications of La- lande and Chaperon 119 Battery, Modifications of Pog- gendorff's 106 Battery, Nomenclature of Pri- mary 95 Battery on Open Circuit, Dis- charge of Storage 144 Battery, Parts of Primary. ... 93 Battery, Partz's 109 Battery, Plante's 128 Battery, Poggendorff's 105 Battery, Polarization of Pri- mary 96 Battery, Radiguet 108 Battery, Requirements of a Storage 128 Battery, Sand Type of Dan- iell's. Drop 82 Calculations for Series Distri- bution 475 Calculations, Voltage 92 Calibration 524 Calorimeter. Hare's 99 Camacho Cascade Battery.... 107 Candle, .Jablochkoff 561 Candle, Standard, English.... 567* Candle-Power in Arc Light, m Watts per 579j Candle-Power in Incandescent fl Lamps, Watts per 580H INDEX. 741 Candle-Power of Incandescent Lamps 576 Candle-Power, Spherical 574 Capacity 47, 388 Capacity, Composition of Re- sistance,. Inductance, and. . 343 Capacity, Examples of 49 Capacity of Cable, Determina- tion of 648 Capacity of Condensers 44 Capacity, Ohmic Equivalent of Reactance of 337 Capacity, Reactance of 338 Capacity, Specific Inductive. . . 48 Capacity, Storage 130 Carboning a Lamp 561 Carbonization 524 Carbon-Feed Lamps 549 Carbon Holder, Globe and 547 Carbon Holders 550 Carbon Negative Plates 103 Carbon Transmitters, Loose. . . 681 Carbons, Arc Light 539 Carbons, Duration of 545 Carbons, Inclosed-Arc . 547, 559, 560 Carbons, Positive and Nega- tive 535, 560 Carbons, Quality of 538 Carbons, Wearing of 539 Cardew Voltmeter 463 Car, Economical Running of. 597 Car, Jerking 601 Car Heating 601 Car, Leaving the 598 Car Motor, Construction of . . . 588 Car Motors, Horse-Power of.. 586 Car, Reversing the 598 Cascade Battery. Camacho. . . . 107 Cathode, Position of Anode and 670 Causes of Lag and Lead 341 Cell 96 Cell, Modification of Gravity. 116 Cell, The Primary Battery 93 Cells, Counter, E.M.F 165 Cells, Insulation of Storage Battery 161 Cells of Storage Battery, End 164 Cells, Short-Circuiting of Sin- gle 152 Cells, Storage Battery 161 Center, Armature out of 429 Centering of Armature 428 Change, Graphic Representa- tion of Rate of 323 Change, Rate of 323 Changing Voltage 400 Characteristic Curves. See Curves. Characteristic. Charge, E.M.F. and the Static 58 Charge, First 150 Charge of Storage Battery, The ■. 145 Charging 43 Charging, English Rule for... 151 Charging from Lighting Cir- cuits, Connections for 157 Charging Storage Battery.,,. 166 Chemical Action of Storage Batteries 131 Chemical Decomposition, Cur- rent Strength and 90 Chemical Decomposition, E.M. F. in 91 Chemical Decomposition, En- ergy in 91 Chemical Equivalents, Atomic Weights and, 89 Chloride Battery 136 Choke Coils 505 Choking of Transformer 376 Circle, Generating 322 Circle, Interpretation of the Generating 323 Circuit, Action of a 66 Circuit and Inductance, Turns of a 334 Circuit, Action of Arc Lamp on Constant Potential 553 Circuit-Breaker 150 Circuit-Breaker, Magnetic Re- lease Underload 453 Circuit-Breaker, Mechanical Re- lease LTnderload 453 Circuit-Breaker, Reverse Cur- rent 454 Circuit-Brealier, Switch Boxes and, on Car. 590 Circuit-Breakers as Switches.. 454 Circuit-Breakers, Combined . . 454 Circuit-Breakers, Overload. . . . 451 Circuit-Breakers, Underload.. 452 Circuit, Bridged Telephone... 696 Circuit, Condensers in a 64 Circuit, Constant Current .... 78 Circuit, Constant Potential... 78 Circuit, Constitution of a ... . 63 Circuit, Counter and F'orward E.M.F. in Alternating-Cur- rent 334 Circuit, Discharge of Storage Battery on Open 144 Circuit, E.M.F. in Alternating- Current 333 Circuit, Energy and the Mag- netic 172 Circuit, Exciting Series Coils from Main 261 Circuit, Nature of the Mag- netic 174 Circuit, Outer 68 Circuit, Permeance of a Mag- netic 184 Circuit. Polarity of the 159 Circuit, Qualities of a 331 Circuit, Series Telephone 695 Circuit, Short 69 Circuit, Short Circuits in Out- er 432 742 ELECTRICIANS' HANDY BOOK. Circuit, The Electric 63 Circuit, Tlie Magnetic 172 Circuit, Tliree Elements in a. 74 Circuit, Ttiree Factors of Mag- netic 175 Circuit without Resistance. 71 Circuits. Arc and Incandes- cent Lamp 472 Circuits, Appliances and Gene- rators in. i 65 Circuits, Calculation of Resist- ance of Parallel 81 Circuits, Connections for Charging from Lighting.... 157 Circuits, Independent 492 Circuits, Open and Closed.... 64 Circuits without Appliances. 64 Circular Developments 238 Circular Functions, Numerical Value of 34 Circular Mil, Area of 84 Circular Mil System 83 Circular Mil System, Applica- tion of 84 Classification 483 Clerk Maxwell's Rule 213 Closed Circuits, Open and.... 64 Closed-Coil Armatures, Modern Types of 226 Closed - Coil Direct - Current Armature 223 Closet System 484 Clouds, E.M.F. in Thunder... 58 Clutch. The 548 Clutch Stop Adjustment 560 Coherer, Branly's 732 Coherer, Marconi's 736 Coil and Electro-Magnet, Mag- netizing by 197 Coil, Damping 460 Coil. Dimensions of Telephone Induction 686 Coil, Disconnecting or Open- ing Shunt 260 Coil. Efeect of Independent Ex- citation of Shunt 260 Coil, Effect of Telephone In- duction 688 Coils, Arrangement of Resist- ance 627 Coils, Choke 505 Coils. Direction of Current In- duced in 217 Coils from Main Circuit, Excit- ing Series 261 Coils, Heating of Field 429 Coils in Arc Lamp Resistance. 553 Coils in Bracket Telephones, Induction 688 Coils in Comnound Dynamos, Excitation of Field 260 Coils. Modern Arrangements of Resistance , 6'^8 Coils, Pancake 381 Coils, Practical Notes on Re- sistance 631 Coils, Proportional 636 Coils, Reactance or Economy. 545 Coils, Repeating 705 Coils, Resistance 626 Coils, Resistance, Spools for.. 631 Coils, Separate Excitation of Shunt 261 Coils, Telephone Induction. 684 Coils, Winding Armatures with Formed 301 Collecting or Slip Rings. 219 Collector Rings 419 Colors, Distinguishing, of Wires 722 Commercial Rating of Arc Lamps 542 Commutator Bars. Bad Con- tacts between Winding and. 419 Commutator Bars, Loose 420 Commutator Connections. .238, 245 Commutator Connections, De- velopment of 240 Commutator Connections of Ring Armature 227 Commutator Construction 303 Commutator, Filing 433 Commutator, Material of .... 419 Commutator, Oval 420 Commutator, Position of 305 Commutator, Sandnanering. 483 Commutator, Smoothing .... 433 Commutator, Sparking 'of 424 Commutator Surface, Gummy or Sticky 420 Commutator Surface, Lubricat- ing 420 Commutator, Temperature of.. 419 Commutator. Turning down. 432 Compensated Voltmeter 470 Compensating Resistance 619 Compensator. Inductance .... 743 Concentric Magnets in Lamps. 550 Condenser, Earthing a 44 Condenser, Single Surface 45 Condensers 42 Condensers; Capacity of 44 Condensers in a Circuit 64 Conditions for Inducing Elec- tric Energy 20G Conditions of Sensitiveness... 636 Conductance 69 Conductance and Cross-Sec- lional Area of Conductors.. 8.3 Conductibilitv 69 Conduction, Electrolytic 73 Conduction Interference 714 Conductivity 69 Conductor, Action of a 51 Conductor, Calculation for Conical 486 Conductor in a Field of Force, Motion of 169 Conductor, Inductance React- ance in Subdivided 336 Conductor, Lines of Force Pro- duced by a Curved 169 Conductors, Conductance and Cross-Sectional Area of. 83 Conductors, Cylindrical and Conical 485 Conductors, Eddy Currents in. 272 Conductors, Electrolytic 66 Conductors and Non-Conduc- tors 50 Conductors, Size of, for Plat- ing 669 Conical Conductor, Calculation for 486 Conical Conductors, Cylindri- cal and 485 Connection, Delta or Mesh. 361, 507 Connection in Cable, Making Branch 653 Connection of Stations 734 Connection, Y or Star 359 Connections. Antennae and, in Wireless Telegraphy 735 Connections. Auxiliary Feeder 495 Connections, Booster 406 Connections. Booster and Stor- age Battery 410 Connections, Commutator .238, 245 Connections, Development of Commutator 240 Connections, Drum Armature. 350 Connections, Examining, on Cars 599 Connections for Alternating- Current, Y 506 Connections for Charging from Lighting Circuits 157 Connections in Compound Dynamos, Wrong 432 Connections, Making Storage Battery • 161 Connections, Line 362 Connections, Multipolar Dyna- mo 264 Connections of Ring Armature, Commutator 227 Connections, Switchboard .... 712 Conservation of Electricity.... 57 Constancy of Magnetism 199 Constant-Current Circuit 78 Constant-Current or Series Arc Lamps 551 Constant-Current System 472 Constant-Current System for Arc Lamps, Features of Series or ..." 475 Constant-Current Transform- ers T 387 Constant, Determination of the 620 Constant, Hysteretic 186 Constant of Galvanometer.... 620 Constant-Potential Arc Lamps 555 Constant- Potential Circuit 78 Constant-Potential Systems... 473 Constants. Useful 35 Constitution of a Circuit 63 Contacts between Winding and Commutator Bars, Bad 419 Control, Crocker- Wheeler Speed 414 Controller Points 593 Controller, Rheostat 596 Controller, Series-Parallel. 594 Controller Troubles on Cars.. 600 Controllers 592 Construction, Advantages of Multipolar 252 Construction, Multipolar 350 Conventional Representations of Machines 264 Converter, Functions of a Ro- tary 394 Converter in Three-Wire Sys- tem, Rotary 393 Converter, Rotary 390 Converter, Starting a Rotary.. 394 Cooking and Domestic Heat- ing. Electric 728 Cooking, Power Required for. Cores of Ring Armatures ..... 228 Cotton Waste 439 Coulomb, Hydrogen Liberated by tlie 88 Coulomb, Water Decomposed by the 88 Coulombs, Current, Amperes and 52 Counter Electromotive Force. See Counter E. M. F. Counter E. M. F 333, 536 Counter and Forward E. M. F. 173 Counter and Forward E. M. F. in Alternating-Current Cir- cuit 334 Counter E. M. F. Cells 165 Counter E. M. F., R. I. Drop and 79 Counter E. M. F., Drop Cal- culation, Example of 82 Couple 96 Coupling of Compound Dyna- mos, Parallel 402 Coupling of Shunt Dynamos, Parallel 402 Critical Point of Shunt- Wound Dynamo 281 Crocker-Wheeler Speed Con- trol 414 Crompton-Howell Battery . . . 135 Crushers 413 Current from Alternating Cur- rent, Direct 390 Current, Amperes and Coul- ombs 52 Current and Rate Units. ..... 50 Current Armature, Closed-Coil Direct . . 223 Current, Cause of Form of Alternating E. M. F. and.. 319 Current Circuit, Constant.... 78 Current, Critical 279 Current Curves, Alternating E. M. F. and 320 Current Curves, Drawing B. M. F. and 321 Current Curve. E. M. F. and. 316 Current, Direction of a 55 Current Distribution, Alternat- ing 504 Current Dynamo, Elementary Idea of Alternating 219 Current Dynamo, Pllementary Idea of Direct . 220 Current in Electroplating, Regulation of 661 Cur-rent for Electroplating. . . 660 Current, Ether and 167 Current, Fields of Force and Lines of Force Due to. . . . 55 Current, Form of Alternating E. M. F. and 318 Current, Generation of Alter- natinsr 348 Current, Induced, Develop- ment of 240 Current Induced in Coils, Di- rection of 217 Current Intensity in Plating. . 669 Current Measurement with Potentiometer 640 Current on the Magnet, Ac- tion of a 202 Current, Production of 52 Current. Production of Alter- nating E. M. F. and 318 Current in Rotary Transform- er, Relations of Voltage and 392 Current, Reversing Direction of 416 Current, Speed of a 54 Current, Standard Series Lighting 477 Current Strength 53 Current Strength and Chemi- cal Decomposition . 90 Current, Three-Phase 347 Current, Time Required to Pro- duce a 52 Current to Drop, Relation of. 491 Current, Two-Phase 346 Current, Wattless 246 Current, Y Connections for Alternating 506 Currents in Armature Cores, Eddy 271 Currents in Conductors, Eddy. 272 Currents in Core Disks. Eddy. 271 Currents, Fbucault or Eddy. 215, 271, 429 Currents, Mutual Action of. . 199 Currents in Pole Pieces, Eddy. 272 Curve, Arrival 54 Curve, Droopins? Characteristic 275 Curve, E. M. F'. and Current. 316 Curve of Shunt Dynamo, Total Characteristic 203 Curve, of Shunt Dynamo, Total Current Characteristic 282 Curve, Sine 321 Curve^. Vector Diagram of Sine 325 Curved Co^nductor, Lines of Force Produced by a 169 Curves, Alternating E'. M. F. and Current 320 Curves, B and H 178 Curves, Characteristic.258, 273, 276 Curves, Determination of .... 182 Curves, Drawing Character- istic 277, 321 Curves, General Notes on Characteristic 279 Curves, Hysteresis 185 Curves, Internal Characteristic. 277 Curves, Interpretation of B and H 179 Curves,- Interpretation of Characteristic 276 INDEX. 745 Curves, Ohm-Volt 284 Curves, I'ermeability ISO Curves. Power 345 Curves, Shunt-Wound Dynamo Characteristic 280 Curves, Types of Character- istic 273 Cutting Lines of Force, 205, 209, 224 Cut-Outs 560 Cut-Out, Automatic 150 Cut-Out, Film 478 Cut-Outs, Board and 596 Cut-Outs, Overload and ITnder- load 448 Cycle 316 Damping Air- Vane 461 Damping Coil 460 Daniell Battery Ill, 112 Daniell Battery, Sand Type of 114 Dash Pots 550 Data with Storage Batteries, Manufacturer's 144 Deflection, Direction of .... 637 Degree System 321 Delta or Mesh Connection. 361, 507 Demagnetizing Turns 268 Density, Field 176 Density of a Field of Force. . 172 Densities of Field. Varying. . 267 Depolarizers, Sulphuric and Nitric Acid 110 Depolarizing Mixtures in Pog- gendorff's Battery 109 Deposits. Backing Up 675 Deprez-D'Arsonval Galvanom- eter 611 Detection of the Field of F'orce 168 Determination of Curves.... 182 Determination of Discharge of Storage Battery 145 Dean's Common Battery Sys- tem 698 Decade Plan. The 629 Decomposition, Current Strength and Chemical .... 90 Decomposition, E. M. F. in Chemical 91 Decomposition, Energy in Chemical 91 Developments, Circular 238 Diagram of Sine Curve, Vector 325 Diagrams, Armature Reaction. 266 Dielectrics 48 Difference of Potential, E. M. F. and 61 Diffractive Photometer 574 Dimensions of Telephone In- duction Coil , . 686 Dip Batteries 108 Direct-Current Armature, Closed-Coil 223 Direct-Current Dynamo, Ele- mentary Idea of 220 Direct-Current from Alternat- ing Current 390 Direct-Current Ground Indi- cator 456 Direct-Current Motor and Torque 285 Direct-Current Open Arc 540 Direct-Current Open Arc, Dis- tribution of Light in 541 Direction of Current Induced in Coils 217 Direction of Current, Reversing 416 Direction of Deflection 637 Discharge of Storage Batteries 144 Discharge of Storage Battery, Determination of 145 Discharge of Storage Battery on Open Circuit 144 Disconnecting or ' Opening Shunt Coil 260 Disintegration of Storage Bat- tery 153 Disk Armature 303 Disk, Bunsen 564 Disk, Leeson 565 Disk Winding of Transform- ers 387 Disk Windings 357 Disk- Wound Transformers . . . 380 Disks, Mounting Photometer. . 565 Disks, Eddy Currents in Core. 271 Distortion. Field 265 Distributing Boards 703 Distribution, Alternating-Cur- rent 504 Distribution, Calculations for Se^'ies 475 Distribution, Disadvantages of Parallel 482 Distribution. Elementary Case of Parallel 482 Distribution, Limitations of Series 474 Distribution, Objections to Series 481 Distribution of Light 534 Distribution of Light of Alter- nating-Current Arc Lamps . . 544 Distribution of Light from Arc Lights 582 Distribution of Light in Di- rect-Current Open Arc .... 541 Distribution of Light from In- candescent Lamps 583 Distribution. Parallel 481 Distribution, Series 472 Driving Points ._, 593 Drop and Arc Length, Volt- age 538 Drop and Fall of Potential.. 79 Drop Calculation, Example of Counter E. M. F 82 746 ELECTRICIANS' HANDY BOOK. Drop Calculations, Examples of R. 1 82 Drop in Parallel System, Po- tential 482 Drop of Potential 60 Drop of Potential, Analogies of 60 Drop, Relation of Current to. . 491 Drop, Voltage 536 Drum Armature 231 Drum Armature, Action of . . . 233 Drum Armature Connections . 350 Drum Armature, Winding a. . 241 Drum Armature Winding, Gen- eral Formulas for 246 Drum Armature Winding, Nomenclature for 246 Drum Armature Windings.233, 243 Dry Batteries 121 Duties, Motorman's 597 Dynamic and Static Electri- city 56 Dynamo, Action of Separately- Excited 262 Dynamo and Motor, Inter- changeability of 218 Dynamo and Motor, Reversibil- ity of 285 Dynamo, Balancing 501 Dynamo Characteristic Curves, Shunt-Wound 280 Dynamo, Critical Point of Shunt- Wound 281 Dynamo Connections, Multi- polar 264 Dynamo- Electric Generators... 218 Dynamo, Elementarv Idea of Alternating-Current 219 Dynamo, Elementary Idea of Direct-Current . /. 220 Dynamo Frames, Earthing . . 431 Dynamo, Modern Multipolar.. 250 Dynamo or Motor, Tempera- ture of 439 Dynamo, Separate-Circuit . . . 263 Dynamo, Starting a ....... 428 Dynamo, Telephone Receiver, a 212 Dynamo, Three-Brush 499 Dynamo, Total Characteristic Curve of Shunt 283 Dynamo. Total Current Char- acteristic Curve in Shunt. 282 Dynamos as Boosters, Motor. 408 Dynamos and Magnetos, Reg- ulation of Separately-Ex- cited 262 Dynamos, Excitation of Field Coils in Compound 260 Dynamos. Field Magnet for Multipolar 310 Dynamos, Field Winding of. . 252 Dynamos, Parallel Coupling of 402 Dynamos, Self-Regulation of Compound-Wound 257 Dynamos, Separately- and Self- Excited 263 Dynamos, Series Winding of. 252 Dynamos, Shunt Winding of. . 254 Dynamos, Soft Steel in 181 Dynamos, Varieties of 219 Dynamos, Wrong Connections in Compound 432 Dynamometer, The 39 Dynamometer, Siemens's 622 Economy Coil, Reactance or. . . 545 Economy, Feeder 496 Edison's Meter 513 Edison's Storage Battery.... 140 Edison's Telephone 682 Eddy Currents, Foucault or, 215, 271, 429 Eddy Currents in Armature Cores 271 Eddy Currents in Conductors. 272 Eddy Currents in Core Disks. 271 Eddy Currents in Pole Pieces. 272 Effective Values 328 Effective Values, Formulas for 330 Efficiency of Alternating-Cur- rent Arc Lamps 545 Efficiency of Arc Light 537 Efficiency of Electric Heating 723 Electric Arc, see Arc. Electric Circuit, The 63 Electric-Car Motor, The 584 Electric Cooking and Domestic Heating 723 Electric Energy, Conditions for Inducing 206 Electric Generators, Dynamo. 218 Electric Heating. Economy of. 730 Electricity. Conservation of . . 57 Electricity, Dynamic and Static 56 Electricity, Ether Waves Pro- duced by 50 Electricity, Quantity of. Mean- ing of 44 Electric Resonance 339 Electric Quantity, Storage of. 41 Electrodes, Moving 103 Electro-Chemical Equivalents. 89 Electro-Chemistry, Summary of 90 Electrolyte and Tests, Impuri- ties in 155 Electrolyte, Preparing the . . 155 Electrolyte. Specific' Gravity Variation of Storage Bat- tery 146 Electrolytic Conduction ...66, 73 Electro-Magnet •• . . 188 Electro-Magnet, Magnetizing by Coil and 197 Electro-Magnet, Spiral 189 Electro-Magnet, Tractive Force of the 188 Electro-Magnets, U-Shaped.... 189 Electro-Magnetic Induction . . 205 INDEX. 747 Electro-Magnetic Tractive Power 192 Electrometer, Thomson or Kelvin Absolute 617 Electromotive Force. See E. M. F. Electromotive Force, Counter. See Counter E. M. F. Electroplating 659 Electroplating, Current for... 660 Electroplating, Energy Absorb- ed in 659 Electroplating, General Prin- ciples of 659 Electroplating, Regulation of Current in 661 E. M. F 55 E. M. F., Alternating 316 E. M. F. in Alternating-Cur- rent Circuit 333 E. M. F'. in Chemical Decompo- sition 91 E. M. F. the Cause of Current 59 E. M. F. and Current, Cause of F'orm of Alternating. . . . 319 E. M. F. and Current Curves. 316 E. M. F. and Current Curves, Alternating 320 E. M. F. and Current Curves, Drawing 321 E. M. F. and Current, Form of Alternating 318 E. M. F. and Current, Produc- tion of Alternating 318 B. M. F. and Difference of Potential 61 E. M. F. Drop Calculation, Example of 82 E. ]M. F'. and Energy 56 E. M. F'. Forward 173 E. M. F. by Increasing Turns, Increasing 221 E. M. F. Increasing, by Adding Armature Core . 221 E. M. F. and the Static Charge 58 E. M. F., Counter. See Count- er E. M. F. E. M. F., Production of 56 E. M. F. in Thunder Clouds . . 58 E. M. F., Variations in Im- pressed 216 End Cells of Storage Battery. 164 End Motion in Armature Shaft 428 Energy Absorbed in Electro- plating 659 Energy in Chemical Decompo- sition 91 Energy, Conditions for In- ducing Electric 206 Energy Due to Hysteresis, Loss of 186 Energy, B. M. F. and 56 Energy and the Field of Force 174 Energy of the Field of Force, Potential 173 Energy and the Magnetic Cir- cuit 172 Energy Ftelations 209 Energy, Resistance and 70 English Rule for • Charging. . . 151 E. P. S. Battery 135 Equalizer in Three-Wire Sys- tem, Storage Battery 50 Equivalents, Atomic Weights and Chemical 89 Equivalents, Electro-Chemical. 89 Equivalent of Reactance of Capacity, Ohmic 337 Equivalent of Reactance of In- ductance, Ohmic 336 Ether and Current 167 Ether, Luminiferous 40 Ether Waves Produced by Elec- tricity 50 Evolution, Gas 149 Excitation of Field Coils in Compound Dvnamos 260 Excitation of Shunt Coil, Ef- fect of Independent 260 Excitation of Shunt Coil, Sep- arate 261 External Resistance, Internal and 871 Factor, Form 329 Factor in Alternating-Current Arc, Power 544 Factor. Power 330 Factors of Magnetic Circuit, Three 175 Fall of Potential, Drop and. . 79 Faraday's Law 212 Faure's Battery 130 Faure-Sellon-Volckmar Battery, The 131 Feeder Connections, Auxiliary 495 Feeder Economy 496 Feeders 483, 493 Fiber Suspension 605 Field Coils, Heating of 429 Field Coils in Compound Dyna- mos, Excitation of 260 Field Density 172, 176, 268 Field Distortion 265 Field of Force, The 167 Field of Force, Building up the 173 Field of Force and Lines of Force Due to Current 55 Field of Force, Detection of the 174 F'ieid of Force, Energy and the 174 Field of Force, Iron and the. 175 Field of Force, Motion of Con- ductor in 169 Field of Force, Potential En- ergy of the 173 748 ELECTRICIANS' HANDY BOOK. Field of Force, Varying .... 207 Field Magnets of Alternators. 436 Field Magnet for Multipolar Dynamos 310 Field Magnets, Laminated. . . 314 F'ield Poles 222 Field Poles, Action of on Arm- ature Core 265 Field, The Rotary .. .363, 364, 366 Field, Stray 184 Field, Varying Densities of. . 267 Field Winding, Break in 430 Field Winding of Dynamos, 252, 315 Field Winding, Short Circuits in 430 Field, Wrong Polarity of 417 Fields of Force in Practice. . 209 Fields, Windings for Multi- polar 237 Figure of Merit 622 Film Cut-Out 478 Filament, Occlusion of Gases by Incandescent Lamp .... 525 Filaments, Metallic 530 Filaments, Oxide 530 Filaments, Squirted 524 Filaments, Tamidine 523 Filing, Commutator 433 Fishing for Bell Wires 719 Five and Seven-Wire Systems. 502 Flashing Incandescent Lamp Filaments 524 Flashing, Lowering of Resist- ance of Incandescent- Lamp Filaments hy 525 Flashing, Making Joints in Incandescent Lamps 525 Fleming's Rule 212 Floating Storage Battery.. 166, 410 Forbes' Meter 514 Force, Cutting Lines of.. 209, 224 Force of the Electro-Magnet, Tractive 188 Force, Electromotive. See B. M. F. Force. TTie Field of, etc. See Field of Force. F'orce, Leakage of Lines of. . 183 Force, Magnetic 176 Force, Memoria Technica for Lines of 171 Force^ Relation Between Amp- ere Turns and Lines of . . . . 183 Force, Spreading of Lines of. 188 Force, Threading, Interlinking and Cutting Lines of 205 Force, Utility of Conception of Lines of 171 Form Factor 329 Forming Storage Batteries. . 129 Form of Alternating B. M. F. and Current 318, 319 Formula, Bipolar Winding by. 247 F'ormula, Multipolar Winding by 248 Formulas, Bipolar Winding. . 247 Formulas for Drum Armature Winding. General 246 Forward EL M. F., Counter and 173 Foucault or Eddy Currents, 215, 271, 429 Foucault's Photometer 572 Frame, Short Circuits Between Armature Windings and . . 435 Frequency 316 Frequency, Length of Wave and 319 Fuller's Mercury-Bichromate Battery 106 Function of a Storage Battery 128 Functions, Trigonometric .... 33 Fundamental Note 677 Furnaces, Electric 723 Fuses, Safety 441, 448 Fuses, Safety, in Cars 599 Galvanic Pile 97 Galvanometer 604 Galvanometer, Astatic 605 Galvanometer, Ballistic ..... 610 Galvanometer, Constant of . . . 620 Galvanometer, Deprez-D'Arson- val 611 Galvanometer, Magneto Bell as 655 Galvanometer, Reflecting. . 606, 609 Galvanometer Resistance .... 622 Galvanometer, Shunts 618 Galvanometer, Shunt to the . . 636 Galvanometer, Simple 604 Galvanometer, Sine 616 Galvanometer, Suspension Fiber for 605 Galvanometer, Tangent 615 Galvanometer, Thomson or Kelvin 609 Galvanoscope 636 Galvanoscope Cable and Line Tests 650 Galvanoscope, Telephone as. . 653 Gas Battery, Grove's 126 Gas Evolution 149 Gassing 149 Gassing, Indications from . . 156 Gauge, American Wire 85 Gauges, Wire 85 Gauss. The 178 Generating Circle 322 Generating Circle, Interpreta- tion of the 323 Generation of Alternating Cur- rent 348 Generator, Magneto 250 Generator Without Motion.. 210 Generator and Motor Con- nected 285 Generator, Separately-Excited. 261 INDEX. 749 Generators in Circuits, Appli- ances and 65 Generators, Dynamo-Electric. . 218 Gibbs' Battery 105 Globe and . Carbon Holder... 547 Globe, The Inclosing 559 Gold-Plating 667 Gould Storage Battery 132 Graduation of Voltmeter Scales 463 Gramme Ring, The 226 Graphic Representation of Rate of Change 323 Gravity Battery 114 Gravity Cell, Modification of. 116 Gravity Variation of Electro- lyte, Specific 146 Greek Letters 34 Grenet's Battery 108 Ground Alarm 457 Ground, Bad 598 Ground, Hand Magneto Test for 657 Ground Indicator, Alternating- Current 456 Ground Indicator, Direct-Cur- rent 456 Grounding Wires 721 Grouping of Windings 350 Grove's Batterv 102 Grove's Gas Batterv 126 Gutta-Percha Molds 673 H Armature, Spindle or .... 222 H and B Curves 178 H and B Curves, Interpreta- tion of 179 H and B Syonyms for 178 Hand Magneto Test for Ground 657 Hand Magneto Tests in Gen- eral 656 Hare's Calorimeter 99 Harmonic Signals for Party Lines 701 Heat of Arc 536 Heat in Transformers 384 Heating, C?r 601 Heating, Conditions Causing, 584, 586 Heating, Economy of Electric. 730 Heating by the Electric Arc, Direct 727 Heating, Electric Coolcing and Domestic 723 Heating of Field Coils 429 Heating of Motors 585 Heating of Windings of Stator. Local 436 Helios-Upton Battery 133 Henry. Inductance and the.. 332 Hertz Receiver 732 High Potential, Advjintages of. 476 High-Resistance Measurements 643 High-Voltage Determinations with Potentiometer 638 High-Voltage Parallel Systems 503 Hissing Arc 543 Holder, Globe and Carbon... 547" Holders, Brush 305 Holders, Brushes and Brush. 420 Hook-Switch, The 696 Horse-Power of Car Motors. . 586 Horse-Power Lines 274 Hot Resistance 596 Hot-Wire Voltmeter, The Stan- ley 466 Hot-Wire Voltmeters 466 House Connections, Telephone 693 Hushes Microphone 680 Human Voice, The 678 Running Transmitter 682 Hydrogen Liberated by tlie Coulomb 88 H^ydrogeh to Oxygen, Propor- tion of 88 Hydrometers for Storage Bat- teries 147 Hysteretic Constant 186 Hysteresis 185 Hysteresis Curves 185 Hysteresis. Loss of Energy Due to 186 Hysteresis and Other Receiv- ers 736 Idle Wire 229 Illuminating Power, Standards of 563 Impedance 339 Impressed E. M. F., Varia- tions in 216 Impurities in Electrolyte and Tests 155 Incandescence, Open-Air .... 562 Incandescent Lamp, The 523 Incandescent Lamp Circuits, Arc and 472 Incandescent Lamps, Candle- Powers of 576 Incandescent Lamps, Distribu- tion of Light from 583 Incandescent Lamps, Watts per Candle-Power in 580 iDcandescent Lighting 523 Incandescent Lighting, "Muni- cipal" Series 479 Incandescent Lighting, Series. 477 Inclosed-Arc, Action of 546 Inclosed-Arc Carbons . . . .547, 559 Inclosed-Arc Lamp 545 Inclosed-Arc Lamp, Carbons for 560 Inclosing Globe, The 559 Incubator, The Electric 729 Independent Circuits 492 Independent Excitation of Shunt Coil, Effect of 260 750 ELECTRICIAN Si' HANDY BOOK. Indications From Gassing. 156 Indicator, Alternating-Current Ground 456 Indicator, Direct-Current Ground 456 Individual Transformers .... 505 Individual Voltages of Lamps. 490 Inducing Electric Energy, Con- ditions for 206 Inductance 3.32 Inductance and Capacity, Com- position of Resistance 343 Inductance Compensator, The. 471 Inductance and the Henry... 332 Inductance, Ohmic Equivalent of Reactance of 336 Inductance, Reactance of .... 335 Inductance, Reactance in Sub- divided Conductor 336 Inductance, Turns of a Cir- cuit and 334 Induction 205 Induction, Ampere's Rule Adapted to 213 Induction Coils in Bracket Telephones 688 Induction Coil, Dimensions of Telephone 686 Induction Coil, Effect of Tele- phone 688 Induction Coil, The Telephone 684 Induction, Electro-Magnetic... 205 Induction, Examples of ..... 211 Induction Interference 714 Induction, Laws of 212 Induction Motor, The. 363, 366, 369 Induction Motor, Lenz's Law and the 369 Induction Motor, Polyphase. 4.36 Induction Motor Rotors 436 Induction Motor, Three-Phase. 365 Induction, Two Systems of. 210 Inductive Capacity, Specific. 48 Inductivity 48 Inductor Alternator 356 Iron and the Field of Force.. 175 Iron Negative Plates 101 Iron, Saturation of 177 Inspection of Transformers. 438 Insulation Resistance of Cable 646 Insulation of Storage Battery Cells r ". 161 Insulation Tests. Line 643 Insulation for Transformers. 390 Insulation of Windings 441 Insulator of Magnetism, ISo.. 177 Insulators .....'' 511, 603 Intensity 53 Internal and External Resist- ance 71 Interchangeability of Dynamo and Motor ..." .' 218 Interchangeability of Parts. 439 Interference, Conduction .... 714 Interference, Induction 714 Interlinking and Cutting Lines of Force. Threading 205 Interpretation of B and H Curves 179 Invention of Microphone .... 679 Inverted Addition and Sub- traction 23 Jablochkoff Candle, The 561 Jacket Type Transformers, Shell or 378 Joints in Line Wire 508 Kelvin Absolute Electrometer, Thomson or 617 Kelvin Galvanometer, Thom- son or 609 Kirchofe's Laws 83 Lag 325 Lag, Angle of Lead and .... 326 Lag and Lead, Basis of .... 327 Lag and Lead, Causes of .... 341 Lalande and Chaperon Bat- tery, Modifications of .... 119 Laminated Field Magnets. 314 Lamp Annunciator 709 Lamp, Carboning a 561 Lamp Circuits, Arc and Incan- descent 472 Lamp on Constant Potential- Circuit, Arc 553 Lamp, Direct Photometering of Arc 572 Lamp, Efficiency of Nernst. 533 Lamp, The Incandescent .... 523 Lamp, Inclosed-Arc, Carbons for 560 Lamp. Making Joints by Flashing in. Incandescent. Arc 542 Lamps, Constant-Current or Series Arc 551 Lamps. Constant-Potential Arc 555 Lamps, Direct-Current, Nernst 532 Lamps, Distribution of Light from Alternating-Current Arc 544 ! INDEX. 751 Lamps, Distribution of Light from Incandescent 583 Lamps, Efficiency of Alternat- ing-Current Arc 545 Lamps, Electroplated and Other Joints in Incandescent 526 Lamps, Features of Series or Constant-Current System for Arc 475 Lamps. Inclosed-Arc 543 Lamps, Individual Voltages of 490 Lamps, Maliing Incandescent. 526 Lamps Without Mechanism. 561 Lamps, Noise in Arc 545 Lamps, Relief 478 Lamps, Vacuum Nernst 533 Lamps. Watts per Candle- Power in Incandescent 580 Lap Winding 239, 249 Lap Winding, Multipolar. 246 Lap Winding, Wave and 238 Law, Faraday's 212 Law and the Induction Motor, Lenz's 369 Law, KirchofE's 83 Law, Lenz's 213 Law, Ohm's 74 Law, Right-handed Screw. 204 Laws of Induction 212 Lead 325 Lead, Basis of Lag and 327 Lead, Causes of Lag and .... 341 Lead and Lag, Angle of 326 Leading-in Wires 526 Leakage of Lines of Force .... 183 Leakage. Measurement of Re- sistance 645 Leecon Disk. The 565 Length. Voltage Drop and Arc 538 Length of Wave 318 Lenz's Law 213 Lenz's Law and the Induction Motor 369 Letters, Greek 34 Light of Alternating-Current Arc Lamps. Distribution of. 544 Light from Arc Lights, Dis- tribution of 582 Light in Direct-Current Open Arc, Distribution of 541 Light, Distribution of 534 Lights, Distribution of Light from Arc 582 Light, Efficiency of Arc 537 Light Given by Arc Proper. 543 Light, Mechanical Equivalent of 577 Light, Quality of Arc 580 Light, Watts per Candle- Power in Arc 579 Lighting Circuits. Connections for Charging from 157 Lighting Current, Standard Series 477 Lighting, Incandescent 523 Lighting. "Municipal" Series Incandescent 479 Lighting, Series Incandescent. 477 Lightning Arrester, Double- Pole 522 Lightning Arrester, Low- Equivalent Alternating-Cur- rent 521 Lightrfing Arrester, Tank. 522 Lightning Arrester, Westing- house 521 Lightning Arresters .....jIS, 591 Limitations of Series Distri- bution 474 Line Connections 362 Line Insulation Tests 643 Line of Ohms 278 Line Resistance Tests 643 Line Tests, Galvanoscope Cable and 650 Line Wire. Joints in 508 Lines of Force in Armature, End Leakage of 272 Lines of Force. Cutting. .209, 224 Lines of Force Due to Current, Field of Force and 55 Lines of Force, Leakage of. 183 Lines of Force about a Mag- net, Illustrating 188 Lines of Force, Memoria Technica for 171 Lines of Force Produced bv a Curved Conductor 169 Lines of Force. Relation Be- tween Ampere Turns and. 183 Lines of Force, Spreading of. 188 Lines of Force, Threading, Interlinking and Cutting. Luminescence 530 Luminiferous Ether 40 Lnminomfeter, The 572 Lummer-Brodhim Screen, The. 565 Machine, Starting a 427 Machine, Stopping a 416 Machines, Conventional Repre- sentations of ,. 264 Machines in Series, Shunt'- Woimd 403 Magnet, Action of a Current on the 202 Magnet, Annular Chambered. 191 Magnet, Blow-Out 596 Magnet, Effect of 538 Magnet, The Electro- 188 Mag-net. Illustrating Lines of Force About a 188 Magnet. Magnetizing by Coil and Electro- 197 Magnet for Multipolar Dyna- mos, Field 310 Magnet, The Natural 194 Magnet, The Permanent .... 194 Magnet Poles on Each Other, Action of 195 Magnet, Spiral Electro- .... 189 Magnet, Tractive Force of the Electro- 188 Magnetic Blow-Out Arrester. 518 Magnetic Circuit, The 172 Magnetic Circuit, Energy and the 172 Magnetic Circuit, Nature of the 174 Magnetic Circuit, Permeance of a 184 Magnetic Circuit, Three Fact- ors of 175 Magnetic Force 176 Magnetic Induction, Electro-. 205 Magnetic Needle in Rotating Field, The 364 Magnetic Polarity, Loss of. 417 Magnetic Poles, Attraction and Repulsion of 202 Magnetic Release Starting Box 398 Magnetic Release Underload Circuit Breaker 452 Magnetic Tractive Power, Electro- 192 Magnetism, Ampere's Theory of 200 Magnetism, Ampere's Theory of Terrestrial 201 Magnetism, Constancy of. 199 Magnetism, No Insulator of. 177 Magnetism, Residual 185 Magnetized 199 Magnetizing by Coil and Elec- tro-Magnet 197 Magneto Bell as Galvanometer, The 655 Magneto Generator, The .... 250 Magneto Test for Ground, Hand 657 Magneto, The Telephone 689 Magneto Test for Cross Con- nections,. Hand 658 Magnetos, Regulation of Sep- erately-Excited Dynamos and 262 Magneto Tests, Hand 656 Magnets of Alternators, Field 436 Magnets, Concentric, in Lamps 550 Magnets by Double Touch, Making 196 Magnets, Examples of Perman- ent 198 Magnets, Laminated Field... 314 Magnets, Making U-Shaped. 196 Magnets,. Memoria Technica of 201 Magnets, Multipolar 192 Magnets, Preservation of 198 Magnets by Single Touch, Making 195 Magnets, Steel for 197 Magnets,' U-Shaped Electro-. 189 Main Circuit, Exciting Series Coils from 261 Main, and Leads, Feeders .... 483 Marconi's Coherers 736 Material of Commutator .... 753 Microphone, Hughes 680 Microphone, Invention of .... 679 Mil System, Application of Circular 84 Mil System, Circular 83 Mil, Examples of Area of Cir- cular '. 84 Mil, Area of Circular 84 Moisture in Transformers .... 438 Molds in Bath, Placing 674 Molds, Elastic 673 Molds, Gutta-Percha 673 Molds, Metal 671 Molds, Plaster 672 Molds, Plating on 674 Molds, Preparing 673 Motor and Booster 501 Motor Connected, Generator and 285 Motor, Construction of Car. 588 Motor Dynamos as Boosters.. 408 Motor, The Electric-Car 584 Motor Heating, Cause of. 584 Motor, The Induction 363 Motor, Interchangeability of Dynamo and 218 Motor, Lenz's Law and the Induction 369 Motor Without Load, Speed Regulation of 418 Motor, Operation of Synch- ronous 370 Motor, Refusal of, to Start. 417 Motor, Reversibility of Dyna- mo and 285 Motor Rotors. Induction 436 Motor, Self-Starting Single- Phase 435 Motor, Self-Starting Synch- ronous 373 Motor, Single-Phase Synchron- ous 371 Motor, Synchronous Polyphase. 372 Motor, Temperature of Dyna- mo or 439 Motor, Three-Phase Induction 365 Motor and Torque, Direct- Current 285 Motor Transformer 400, 401 Motor Troubles 600 Motors, Accidents to 415 Motors, Construction of In- duction 369 Motors, Determining the Heat- ing of 585 Motors, Horse-Power of Car.. 586 Motors, Idle 418 Motors, Induction 366 Motors, Polyphase Induction. 436 Motors, Starting and Stop- ping 397, 418 Motors. Synchronous ....369,436 Motorman's Duties 597 Mounting of Ring Armature. 230 Moving Electrodes 103 "Municipal" Series Incandes- cent Lighting 479 Multiple Series 67 Multiple Series System 478 Multiple Switchboard, The. 706 Multipolar Construction. .252, 350 Multipolar Construction, Ad- vantages of 252 Multipolar Dynamo Connec- tions 264 Multipolar Dynamo, Modern. 250 Multipolar Dynamos, Field Magnet for 310 Multipolar Fields, "Windings for 237, 315 Multipolar Lap Windings 246 Multipolar Magnets 192 Multipolar Ring Armature. 231 Multipolar Winding bv Formu- la \ 248 Multipolar Windings 245 Mutual Action of Currents. 199 Nature of the Magnetic Cir- cuit 174 Natural Magnet, The 194 Negative Carbon, Positive and, 535, 560 Negative and Positive Plates. 9o Negative Plate, Aluminium. 101 Negative Plate, Carbon 103 Negative Plates, Iron 101 Nernst Lamp 530, 533 Nernst Lamp, Direct Current. 532 Nernst Lamp Ballast 532 Nernst Lamp Glower 530 Nernst Lamp Glower Terminals 531 Nernst Lamp Heaters 531 Nernst Lamp Vacuum 533 Neutral Points 268 Neutral Wire in Three-Wire System 497-499 Neutral WMre in Y System ... Ohm, British Association Standard 627 Ohm's Law 74 Ohm's Law, Examples of. 75 Ohm's Law, Five Forms of.. 76 Ohmic Equivalent of React- ance of Capacity 337 Ohmic Compensator, The 471 Ohmic Equivalent of React- ance of Inductance 336 Ohms, Line of 278 Ohm-Volt Curves 2S4 Oil 560 Oil Cooling 384 Oil for Filling Transformers, 389, 437 Oiling 440, 674 Oil Switches 447 Open Arc, The Direct-Current 540 Open Are, Distribution of Light in Direct-Current... 541 Open-Air Incandescence 562 Open Circuit, Discharge of Storage Battery on 144 Open and Closed Circuits 64 Open-Coil Armatures 222 Open-Wound Four-Part Arma- ture 230 Opening Shunt Coil, Discon- necting or 260 Operation, Two-Phase 436 Opposition, Quadrature and. 327 Outer Circuit 68 Outer Circuit, Short Circuits in 432 Overtones 677 Over-Compounding 259 Overload Circuit Breakers.... 451 Overload and Underload Cir- cuit Breakers 448 Oxide Filaments 530 Oxygen, Proportion of Hydro- gen to 88 Pacinotti Armature, The 225 Pancake Coils 381 Panels, Switchboard 445 Parallel Circuits, Calculation of Resistance of 81 Parallel-Circuit System 554 Parallel Coupling of Com- pound Dynamos 402 Parallel Coupling of Dynamos 402 Parallel Coupling of Shunt Dynamos 402 Parallel Distribution 481 Parallel Distribution, Disad- vantages of 482 Parallel Distribution, Ele- mentary Case of 482 Parallel, Series and 68 Parallel and Shunt 67 Parallel System, Potential Drop in 482 Parallel Systems, Anti- 488 Parallel Systems, High-Voltage 503 Parts, Interchangeability of. 439 Parts of Primary Battery 93 Party Lines 700 Party Lines, Harmonic Sig- nals for 701 Party Lines, Polarized Bells for 700 Partz's Battery 109 Pasted Plates 135,139 Percentage 20 Permeability 175, 177 Permeability Curves 180 Permeance 175 Permeance of a Magnetic Cir- cuit 184 Permeance of Ring Core 228 Phase 325 Photometer Apparatus 567 Photometer, Bar 563 Photometer Bar, Calculating- Scale of 568 Photometer, Bouguer's 570 Photometer, Diffractive 574 Photometer, Foucault's 572 Photometer Observations .... 569 Photometer, Principle of 563 Photometer, Pupillary 573 Photometer, Shadow 570 Photometering of Arc Lamp, Direct 572 Photomteric Screens 564 Photometric Standards 570 Photometric Standards, Table of 570 Photometry of Arc Lamp .... 576 Pile, Galvanic 97 Pile, Volta's 97 Pile, Zamboni's. 99 Pilot Wires, Pressure Lines or 470 Pitch 677 Plante's Battery 12S Plate, Cadmium 156 Plate, Sounding 677 Plates, Buckling of 153 Plates, Negative and Positive. 