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Class _^JL Book 'f~'/ Z (7?¥ n siht Electrical Engineer's pocket-book: A BAND-BOOK OF USEFUL DATA FOR ELECTRICIANS AND ELECTRICAL ENGINEERS. BY | HORATIO A. FOSTER, Fellow A. I. E. E.; Mem. A. S. M. E. Consulting Engineer. Author of " Engineering Valuation of Public Utilities and Factories." With the collaboration of eminent specialists. SEVEJVT^f^Qf^p^ HE VISED mymm£nTpnmr FOR OFFIQA^JJSE C ACCOUNTED FOR IN tfKBfcwiTH PAR. 693 A. h. NEW YORK: D. VAN NO-STRAND COMPANY 1918. Copyrighted, 1902, 1908, 1913, by D. VAN NOSTRAND COMPANY, New York. gj 3IHT By Exchange Mlddtetown Depot Supply March 10,188! -4 r PREFACE TO THE FIFTH EDITION. ^ £ In appreciation of the very cordial reception accorded the earlier editions of this book, and in recognition of the fact that vast changes and advances have occurred in every branch of electrical engineering since the original publication, the author feels called upon to issue the present revised and enlarged edition. The book as now presented, exceeds the previous editions in magnitude by about 600 pages, while the subject matter of every section has been either com- pletely revised and brought up to date, or entirely re-written. The aim throughout has been to supply in exhaustive and condensed form, the data essential to the engineer engaged in any of the branches of the vast domain of electrical engineering. While our concep- tion of the fundamental principles of electrical science can of necessity have undergone no very considerable alteration, those esse&ttal details which in effect con- stitute thet ^working -data .Qf the practicing engineer have so altered and g^wn : that books published only a few years ago are already obsolete. It is believed that a stage in the progress of electrical engineering standardization has now been reached wherein a com- pilation such as the present can be accepted as embody- ing the vital element to which future advmces will appear to a degree in the relation of superficial alter- ations. The original plan of dividing the subject into a number of sections and having each revised by an iii iV PREFACE TO THE FIFTH EDITION. eminent specialist in that particular field has again been followed. Aside from the easy accessibility afforded, this plan of construction is valuable only in proportion to the weightiness of the authorities entrusted with the revision of the several divisions, and it is confidently believed that a perusal of the names heading the sections will lead to the conviction that a more approved and authoritative organization could not have been wished for. The several con- tributors are widely known and recognized as among the first of their respective specialties, and it is be- lieved that the general average of excellence assured by their collaboration surpasses that of any compila- tion of the kind previously attempted. Each section is complete in itself, but needless repetition has been avoided by the free use of cross references through the medium of the very extensive index. Attention is directed to the large quantity of new matter, appearing for the first time in print, in the several sections. In the section on Conductors, e.g., the tables of Inductance, Capacity and Impedance, will be found new and original. Many sections, e.g., Street Railways, Photometry, Conductors, Lighting, Roentgen Rays, etc., are pointed out as examples of exhaustive though condensed presentation. The mechanical section has been treated with the same care and attention as the electrical. The matter has been confined to the requirements of the electrical trades and sciences, the inclusion of the usual mathematical tables and data found in the commonly used handbooks having been avoided. These tables being easily accessible, and the present PREFACE TO THE FIFTH EDITION. V edition being already of great magnitude, this exclu- sion will be appreciated. An important feature of the present volume will be found in the voluminous and studiously developed index and table of contents. The index is as com- plete as the limitations of manipulative facility will permit, and is calculated to render the finding of the particular phase of the subject sought a matter of least possible labor. The table of contents is designed to supplement and extend the use of the index, and in conjunction with the marginal thumb-index will render instantaneous the location of sections and subdivisions. The careful and lengthy work of revision and search leads the author to believe that the number of errors cannot be large, and he ventures to express the hope that readers discovering any will have the kindness to bring them to his attention. In conclusion the author begs to express his grati- tude to the many contributors for their cooperation, and to the publishers for their painstaking effort and generosity in making so handsome and substantial a volume. HORATIO A. FOSTER. 100 Broadway, New York. June 1, 1908. PREFACE TO THE SEVENTH EDITION. No attempt has been made in this edition to add new matter nor to make radical changes in the old, but in a few cases substitution has been made, as in the latest revision of the Standardization Rules of the Am. Inst. E. E., and some changes in the text and cuts in the chapter on Switchboards. A number of typographical and other errors have been corrected. HOEATIO A. FOSTER. 43 Exchange Place, New York, April 1, 1913. LIST OF CONTRIBUTORS. I Section. Symbols, Units, Instruments Measurements Revised by ( W. N. Goodwin, Jr. \ J. Frank Stevens. jW. N. Goodwin, Jr. I Prof. Samuel Sheldon. Magnetic Properties of Iron j Townsend Wolcott. Electromagnets <Prof. Samuel Sheldon. Properties of Conductors . ^ Properties of Conductors [ Harold Pender, Ph.D. Carrying A.C. Currents . * Dimensions of Conductors for Distribution Systems. Underground Conduit Construction.  and Design of Dynamos and Motors :} Cecil P. Poole. Tests of Motors Dynamos and ( Cecil P. Poole. < E. B. Raymond. Alternating Current Ma- ( E. B. Raymond, chines < Cecil P. Poole. The Static Transformer .. Standardization Rules . .. Electric Lighting, Incan- descent Electric Lighting, Arc. ( W. S. Moody. i K. C. Randall. A.I.E.E. j Dr. C. H. Sharp. J. H. Hallberg. vii Vlll LIST OF CONTRIBUTORS Illuminating Engineering Electric Railways .. Electrolysis Transmission of Power Storage Batteries . .. Switchboards . . . .. Dr. C, H. Sharp. rA. H. Armstrong. C. Renshaw. N. W. Storer. Milton W. Franklin, M.A, A. A. Knudson. Dr. F. A. C. Perrine. Lamar Lyndon. (H. W. Young. B. P. Rowe. E. M. Hewlett. M. C. Rypinski. Lightning Arresters .... Townsend Wolcott. to i *«_ M^x ( H. W. Young. Electricity Meters ..... | william Bradshaw. Telegraphy Chas. Thorn. Wireless Telegraphy ... F. K. Vreeland. Telephony J. Lloyd Wayne, 3d. Electricity in the U. S. Army Grahame H. Powell. Electricity in the U. S. Navy J. J. Crain. Resonance Lamar Lyndon. Electric Automobiles . . . Alexander Churchward. Electrochemistry and Elec- ( Prof. F. B. Crocker, trometallurgy .... I Prof. M. Arendt. X-Rays Edward Lyndon. ^^w^"^ C°0kinS j Max Loewenthal, E.E. and Welding ' Lightning Conductors . . . Prof. Alex. G. McAdie. Mechanical Section _ . j W- Wallace Christie. Index Max Loewenthal, E.E. SECTIONS. Page SYMBOLS, UNITS, INSTRUMENTS 1 MEASUREMENTS 55 MAGNETIC PROPERTIES OF IRON 89 ELECTROMAGNETS 108 PROPERTIES OF WIRES AND CABLES 131 PROPERTIES OF CONDUCTORS CARRYING A.C. CURRENT 236 DIMENSIONS OF CONDUCTORS FOR DISTRIBUTION SYSTEMS 260 STANDARD SYMBOLS FOR WIRING PLANS, N. E. C. A. . 299 UNDERGROUND CONDUITS AND CONSTRUCTION .... 301 CABLE TESTING 321 DIRECT-CURRENT DYNAMOS AND MOTORS 334 TESTS OF DYNAMOS AND MOTORS 378 ALTERNATING-CURRENT MACHINES 404 STATIC TRANSFORMER 443 STANDARDIZATION RULES A. I. E. E 501 ELECTRIC LIGHTING 528 ILLUMINATING ENGINEERING 584 ELECTRIC RAILWAYS 612 DETERIORATION OF METALS BY ELECTROLYSIS ... 852 TRANSMISSION OF POWER . 864 STORAGE BATTERIES 872 SWITCHBOARDS 906 LIGHTNING ARRESTERS ... 980 ELECTRICITY METERS 997 TELEGRAPHY 1040 WIRELESS TELEGRAPHY 1055 TELEPHONY 1069 USE OF ELECTRICITY IN U. S. ARMY . . c 1123 ELECTRICITY IN U. S. NAVY 1153 RESONANCE 1215 ELECTRIC AUTOMOBILE 1224 ELECTROCHEMISTRY AND ELECTRO-METALLURGY . . . 1229 X-RAYS 1248 ELECTRIC HEATING, COOKING, AND WELDING .... 1256 LIGHTNING CONDUCTORS 1277 FOUNDATIONS AND STRUCTURAL MATERIALS 1289 STEAM 1327 WATER-POWER 1460 SHAFTING, PULLEYS, BELTING, ROPE-DRIVING .... 1481 MISCELLANEOUS TABLES 1499 POWER REQUIRED TO DRIVE MACHINERY 1515 INDEX . . i533 ix ( TABLE OF CONTENTS. ELECTRICAL SECTION. SYMBOLS, UNITS, INSTRUMENTS. Page Electrical Engineering Symbols 1 Electrical Engineering Units 2 Symbols for Physical Quantities (Table) 6 International Electrical Units and Measurements 10 Equivalent Units, Energy and Work (Table) 12 Closed Circuit Cells 14 Open Circuit Cells 15 Dry Batteries , , 18 Standard Cells 19 Grouping of Battery Cells . . . = 19 Galvanometers 21 Resistance Standards 30 Wheatstone Bridge , 31 Water Rheostats . . . 33 Galvanized Iron Wire, Properties of 34 Condensers 35 Specific Inductive Capacity of Gases (Table) 35 Specific Inductive Capacity of Solids (Table) 36 Specific Inductive Capacity of Liquids (Table) . 37 Specific Inductive Capacity 38 Electrometers 40 Voltmeters 40 Ammeters 41 Electro-Dynamometers , 42 Wattmeters 42 Kelvin's Composite Electric Balance 43 Potentiometer . . . , . 47 Instruments and Methods of Determining Wave Forms 50 Oscillograph 52 MEASUREMENTS. Elementary Laws of Electrical Circuits ............. 55 Resistance Measurements 56 Resistance of Galvanometers 60 Resistance of Batteries . 60 Resistance of Aerial Lines and House Circuits 61 xi Xll TABLE OF CONTENTS. Page E.M.F. Measurements 62 Capacity Measurements 63 Electromagnetic Induction 64 Coefficient of Self Induction 65 Measurement of Self Inductance 66 Measurement of Mutual Inductance 67 Measurement of Power in A.C. Circuits 69 Tests with Voltmeter 74 E.M.F. of Batteries 74 E.M.F. of Dynamos , 74 Comparison of E.M.F. of Batteries 76 Resistance Measurement with Voltmeter 78 Resistance Measurement with Voltmeter and Ammeter 78 Measurement of Very Small Resistances 79 Measurement of Insulation Resistances 80 Measurement of Insulation Resistance of Dynamos . . 86 Measurement of Insulation Resistance of Motors 87 Measurement of Resistance of Batteries 87 MAGNETIC PROPERTIES OF IRON. Data for (£-3C Curves (Table) 89 Permeability at High Flux Densities (Table) 91 Methods of Determining Magnetic Qualities of Steel and Iron ... 91 Permeameters 94 Core Losses , 98 Hysteretic Constants for Different Materials (Table) 99 Hysteresis Loss Factors (Table) 99 Hysteresis Factors for Different Core Densities (Table) 100 Hysteresis Tests 101 Hysteresis Meter 102 Eddy Current Factors for Different Core Densities (Table) 106 Specific Energy Dissipation in Armature Core 107 ELECTROMAGNETS. Principle of Magnetic Circuit 109 Traction 110 Magnetization and Traction of Electromagnets (Table) Ill Winding of Electromagnets 112 Resistance of Magnet Wire at 140° F. (Table) 112 Relation between Wire Length, Size and Turns per Volt (Table). . . 114 Correcting Length of Magnet Coil (Table) 117 Linear Space Occupied by Single Cotton-Covered Wire (Table) . . . 121 Linear Space Occupied by Double Cotton-Covered Wire (Table) . . 123 Alternating Current Electromagnets 127 Heating of Magnet Coils 127 Law of Plunger Electromagnet 127 Pull and Ampere-Turn Factors (Table) 128 TABLE OF CONTENTS. Xlll PROPERTIES OF WIRES AND CABLES. Page Units of Resistance 131 Specific Resistance, Relative Resistance and Relative Conductivity 132 Temperature Coefficient (Table) 133 Physical and Electrical Properties of Various Metals and Alloys (Table) 134 Wire Gauges (Table) 141 Wire Strands 142 Physical Constants of Copper Wire (Table) 143 Effect of Admixture of Copper with  Standard Rubber Covered Wire Cables 161 Standard Conductor, National Electric Code, G. E. (Table)  Insulated Cables (Table) 0 ......... . 174 Cambric Insulated Cables (Table) 178a Enameled Wire (Table) 187b Telephone Cables (Table) 188 Telegraph and Submarine  Cost of Aluminum and Copper for Equal Cond. (Table) 195 Comparison of Aluminum and Copper for Equal Length and Con- ductivity (Table) 195 Resistance of Solid Aluminum Wire 62% Conductivity (Table) . . 195 Stranded Weatherproof Aluminum Wire (Table) . 197 Dimensions and Resistance of Stranded Aluminum Wire (Table) . 198 Aluminum for High Tension Transmission Lines 199 Iron and Steel Wire, Physical Constants (Table) . 199 Double Galvanized Telegraph and Telephone Wires (Table) . .  . . 203 Manganin 203 Electrical Properties and Constitution of Manganin (Table) . . . 204 Dimensions, Resistance and Weights of Resistance Wires (Table) . 204 Resistance Ribbon, la la, Quality 205 Krupp's Resistance Wires  208 Carrying Capacity of Wires for Interior Wiring (Tables) 209 XIV TABLE OF CONTENTS. Page Carrying Capacity of Rubber Insulated Cables (Table) 210 Heating of Cables in Multiple Duct Conduit 210 Watts Lost in Single-Conductor Cables (Table) 212 Current Carrying Capacity of Lead-Covered Cables 213 Fusing Effects of Electric Currents 217 Tension and Sag in Wire Spans 218 Calculation of Vertical Sag , . 222 Properties of Dielectrics 227 Dielectric Strength of Rubber 229 Dielectric Strength of Gutta-Percha 232 Dielectric Strength of Air 233 Puncturing Voltage of Mica (Table) 234 Minimum Size of Conductors for High Tension Transmission . . . 235 PROPERTIES OF CONDUCTORS CARRYING ALTERNATING CURRENTS. Skin Effect Factors at 20° F. (Table) 237 Self Induction and Inductive Reactance of Circuits 238 Self Induction of Iron Wire 240 Self Induction of Solid Non-Magnetic Wire (Table) 241 Inductive Reactance of Solid Non-Magnetic Wire (Table) .... 242 Inductive Reactance of Loop of Three-Phase Line (Table) .... 245 Inductive Reactance of Solid Iron Wire (Table) 248 Capacity, Capacity Reactance and Charging Current of Transmission Circuits formed by Parallel Wires 248 Capacity of Transmission Circuits formed by Parallel Wires (Tables) 252 Simple Alternating Current Circuits, Definitions 259 DIMENSIONS OF CONDUCTORS FOR DISTRIBUTION SYSTEMS. Kelvin's Law 261 Calculation of Transmission Lines 264 Effect of Line Capacity 264 Formulae for Cross Section, Weight and Power Loss (Table) . . . 265 Cross Section, Resistance and Reactance Factors (Table) .... 266 Capacity Susceptance of Two Parallel Wires (Table) 269 Numerical Examples of Calculations of Wiring Systems 271 Transmission Line of Known Constants 274 Transmission Line Formulae (Table) 275 Parallel Distribution 277 Calculation of Cross Section, Weight, etc., of Lines 277 Chart and Table for Calculation of Alternating Current Lines . . . 279 Determination of Size of Conductors for Parallel Distribution of Direct Current 284 Transposition of Lines 285 Loss in Sheath of Three-Conductor Lead-Covered Cables 293 Bell Wiring 293 Gas Light Wiring 295 Wiring for Generators, Motors, Transformers, etc 295 Wiring for Induction Motors . 296 Connections of Transformers for Wiring . . 297 TABLE OF CONTENTS. XV STANDARD SYMBOLS FOR WIRING PLANS AS ADOPTED BY THE NATIONAL ELECTRICAL CONTRACTORS' ASSOCIATION. UNDERGROUND CONDUITS AND CONSTRUCTION. Page Cost of Manholes in Dollars (Table) . . 302 Cost of Sewer Connections in Dollars (Table) 303 Constant Cost per Conduit Foot for Manholes in Dollars 304 Cost of Paving per Square Yard in Dol-ars (Table) ........ 305 Cost of Street Excavation per Conduit Foot (Table) 306 Constant Cost per Conduit Foot in Dollars (Table) 306 Cost of Duct Material in Place (Table) . 307 Cost per Conduit Foot in Cities (Table) 307 Underground Work at New Orleans (Table) 308 Boston Edison Co. Construction 309 Itemized Cost of Conduit (Table) 316 Estimating Cost of Conduit (Table; 317 Estimating Cost of Manholes (Table) 317 Grouping of Ducts in Manholes 318 Underground Cables 319 Cable Heads 320 CABLE TESTING. Insulation Resistance Tests 321 Testing Joints of Cables 323 Capacity Tests of Cables 324 Locating Breaks by Capacity Tests 327 Locating Crosses in Cables 327 Locating Faults in Cables 328 Copper Resistance or Conductivity of Cables 330 Testing Submarine Cables During Manufacture and Laying 331 Locating Faults in Underground Cables 331 High Voltage or Dielectric Tests of Cables 332 DIRECT-CURRENT DYNAMOS AND MOTORS. Notation 334 Fundamentals 336 External Characteristics 337 Magnetic Distribution 340 Armatures 341 Armature Windings , . . 342 Balancing the Magnetic Circuits in Dynamos 349 Heating of Armatures 349 Armature Reactions 350 Commutators and Brushes 351 Field Magnets 352 Cooling Surfaces of Field Magnets (Table) 352 Gyrostatic Action on Dynamos in Ships 352 Direct-Current Motors 353 Leonard's System of Motor Control 354 ( XVI TABLE OF CONTENTS. Page Three-Wire System for Variable Speed Motor Work ........ 354 Practical Dynamo Design 355 Armature Details 356 Armature Losses 358 Commutator and Brushes 361 Air Gap and Pole Face 363 Field Magnets 364 Dynamo Efficiency 370 Armature Slot Sizes for Arrangement of Standard Wires (Table) . . 372 Trial Armature Coil Slot Depths (Table) 373 Trial Values for Minimum of Armature Coils (Table) 373 Trial Values for Maximum Turns per Coil (Table) 374 Trial Values for Current-Carrying Capacity of Armature Conductors (Table) 375 Barrel Armature Winding Constants (Table) 376 Average Magnetic Leakage Coefficients (Table) 376 Average Dynamo Efficiencies (Table) 377 TESTS OF DYNAMOS AND MOTORS. Temperature Tests 378 Overload Tests 381 Insulation Tests . ■ 381 Strain Tests , 381 Regulation Tests of Dynamos, Shunt or Compound, and Alternators . 382 Regulation Tests of Motors, Shunt, Compound and Induction .... 383 Efficiency Tests of Dynamos 383 Core Loss Test and Test for Friction and Windage 383 Brush Friction Test 384 Separation of Core Loss into Hysteresis and Eddy Current Loss . . . 385 Kapp's Test with Two Similar Direct-Current Dynamos 387 Electric Method of Supplying the Losses at Constant Potential . . . 389 Calculation of Efficiencies 391 Hopkinson's Test of Two Similar Direct-Current Dynamos 393 Fleming's Modification of Hopkinson's Test . 394 Motor Tests 394 Test of Street Railway Motors 397 Tests for Faults in Armatures . , . , . 402 ALTERNATING-CURRENT MACHINES. Energy in an Entirely Non-inductive and Balanced Three-Phase Cir- cuit 405 Energy in Non-inductive Three-Phase Circuits 406 Copper Loss in Armatures of Alternators 407 Compensated Revolving Field Alternators .■"■■. 409 Regulators for Alternating Current Generators 409 Alternating Current Armature Windings 410 Armature Reaction of an Alternator 414 Synchronizers 416 Inductor Type Synchroscope 0 . 417 Note on the Parallel Running of Alternators »,•-•'•• 419 TABLE OF CONTENTS. XV11 Page Synchronizing .......... 421 Alternating Current Motors 421 Elementary Theory of the Polyphase Induction Motor 422 Analytical Theory of Polyphase Induction Motor . 423 Speed of Rotary Field for Different Numbers of Poles and for Various Frequencies (Table) . 424 Slip of Induction Motors (Table) 425 Core of Stator and Rotor 425 Number of Slots in Field-Frame of Induction Motors (Table) .... 426 Rotor Slots for Squirrel Cage Induction Motors (Table) 427 Flux Densities for Induction  Direct-Current Boosters 435 Rotary Converters 436 Value of Alternating Current Voltage and Current in Terms of Direct Current (Table) 438 Converter Armature Windings 441 Connection of Transformers and Rotary Converters 442 Current Densities of Various Materials 442 THE STATIC TRANSFORMER. Cores of American Transformers 443 Transformer Equations 446 Features of Design ..... . 447 Insulation 447 Temperature 447 Efficiencies 453 Magnetic Fatigue or Aging of Steel and Iron 455 Change of Hysteresis by Prolonged Heating (Table) 457 Regulation 458 Comparative Expense of Operating Large and Small Transformers . 458 Power Factor 458 Testing Transformer 459 Sparking Distances Across Needle Points 462 Transformer for Constant Secondary Current 462 Economy Coils or Compensators 463 Transformers for Constant Current from Constant Potential .... 464 General Electric Constant Current Transformers 464 Reactance for Alternating Current Arc Circuits 466 Potential Regulators 467 Separate Circuit Regulators 469 Three-Phase Regulators 469 Three-Phase Transformers , 470 Ratio of Transformation in Three-Phase Systems 471 Transformer Connections 472 Single-Phase Transformer Connection" , , 472 ( XV111 TABLE OF CONTENTS. Page Two-Phase Transformer Connections 473 Three-Phase Transformer Connections 473 Arrangement of Transformers for Stepping Up and Down for Long Distance Transmission 475 Three-Phase to Six-Phase Connections 475 Methods of Connecting Transformers to Rotary Converters 476 Converter and Transformer Connections 477 Measuring Power in Six-Phase Circuits .............. 477 Y or A Connection in Transformers 478 Grounding the Neutral 478 Unstable Neutral 479 Rise of Potential 479 General Electric Company Mercury Arc Rectifiers 480 Westinghouse Mercury Arc Rectifier Outfits 481 Transformer Testing 482 Insulation Test 483 Core Loss and Exciting Current 485 Measurement of Resistance 486 Impedance and Copper-Loss Tests 487 Heat Tests 489 Regulation 491 Efficiency 493 Polarity 495 Data to be Determined by Tests 495 Methods of Testing Transformers 496 Specifications for Transformers 498 Rise of Temperature 498 Location of Transformers 499 Transformer Oil 500 STANDARDIZATION RULES OF THE AMERICAN INSTITUTE OF ELECTRICAL ENGINEERS. Definitions and Technical Data 501 Performance, Specifications and Tests 506 Voltages and Frequencies 521 General Recommendations 522 Appendices and Tabular Data 523 ELECTRIC LIGHTING. Light and Laws of Radiation 528 Intrinsic Brightness of Different Sources of Light (Table) 529 Units and Standards of Light 530 Photometers 534 Incandescent Lamps 540 Distribution Curves 540 Current Taken by Various Lamps (Table) 542 Proper Use of Incandescent Lamps 544 Life and Candle Power of Lamps 644 Importance of Good Regulation , 545 TABLE OF CONTENTS. xix Candle-Hours — Regulation of Lamp Values 546 Variation in Candle-Power and Efficiency 547 Lamp Renewals 547 Luminosity of Incandescent Lamps 548 Metallized Carbon or Gem Lamps 549 Tantalum Lamps 549 Tungsten Lamps 553 Effect of Changes of Voltage 553 When and How Incandescent Lamps are Used (Table) 555 Totals of Average Consumption, Showing Yearly Consumption per 16-c.p. Lamp Connected (Table) 555 Cooper-Hewitt Mercury Vapor Lamp 558 Nernst Lamp 562 Tests of Various Illuminants by National Electric Light Assn. . . . 564 Moore Vacuum Tube Light 565 Efficiency of Moore Tube 566 Arc Lamps and Arc Lighting . . 568 Classification of Arc Lights 568 Open Arc Lamps 569 High Tension Lamp 570 Magnetite Arc Lamp 570 Flaming Arc Lamps 572 Searchlight Projectors 575 Enclosed Arc Lamps . . . . 575 Tests of Arc Light Carbons 577 Enclosed Arc Carbons 578 Sizes of Carbons for Arc Lamps (Table) 578 Carbons for Searchlight Projectors (Table) 579 Carbons for Focusing Lamps (Table) 579 Candle Power of Arc Lamps 579 Arc Light Efficiency 580 Heat and Temperature Developed by the Electric Arc 581 Balancing Resistance for Arc Lamps on Constant Potential Circuit . 581 Street Lighting by Arc. Lamps 582 Light Cut Off by Globes 582 Trimming Arc Lamps 583 ILLUMINATING ENGINEERING. Intensity of Illumination at Various Points (Table) 586 Graphic Illuminating Chart 587 Required Illumination for Various Classes of Service (Table) .... 589 Saving by the Use of High-Efficiency Lamps (Table) 589 Experimental Data on Illumination Values 592 Coefficients of Reflection 593 Comparative Values of Illumination and Efficiency of Various Methods of Lighting (Table) 594 Interior Illumination 596 Data on Arc Lighting Installations in Operation (Table) 598 General Illumination ... 599 i XX TABLE OF CONTENTS. Correct Use of Light ............ 600 Distribution of Light by Incandescent Lamps 601 Concealed Lighting Systems 601 Illumination Intensity Required for Reading ...... . ... . 602 Lighting Schedules 603 Lighting Table for New York City 604 Hours Artificial Light Needed Each Month (Table) 606 Humphreys' Lighting Tables 607 Hours of Burning Commercial Lights (Table) . . . . 611 Graphic Lighting Schedule for London, England ......... 611 ELECTRIC RAILWAYS. Grades and Curves. ■•••...,.• 612 Systems of Operation 613 Car Equipments. 613 Locomotives 614 Weights of Rails (Table) 615 Radius of Curves for Different Degrees of Curvature (Table) .... 617 Grades in per Cent, and Rise in Feet (Table) 617 Elevation of Outer Rail on Curves (Table) 617 Equipment Tables 618 Durability of Railroad Ties (Table) 619 Paving 619 Estimate of Track Laying Force. 619 Railway Turnout 620 Electric Railway Automatic Block Signalling 622 Requirements of a Signal System 623 Typical Automatic Two-Line Wire, Non-Interfering Block Signal. 624 Distributed Signal Block System 627 Material for One Mile Overhead Line Street Railway (Table) .... 628 Estimated Cost of One Mile Double Track Overhead Street Rail- way System 629 Standard Iron or Steel Tubular Poles 629 Standard Pole Line Construction 630 Double Track Center Pole Construction 631 Plate Box Poles 632 Tubular Iron or Steel Poles (Table) 633 Cubic Contents of Wooden Poles (Table) 633 Average Weights of Various Woods (Table) 634 Dip in Span Wire 634 Side Brackets 635 Trolley Wire Suspension 637 Guard Wires 639 Catenary Trolley Construction for A.C. Railways 640 Properties of Galvanized Steel Strand Cable (Table) 642 Line Material per Mile of Tangent Track for Catenary Construction (Table) 643 Staggering Trolley for Sliding Contact 644 Bracket Construction 644 TABLE OF CONTENTS. XXI Page Span Construction 644 Hangers per Span for Tangent Track (Table) 646 Hangers per Span for Pull-Off Curve Construction (Table) 647 Energy Consumption 652 Constants for Determining H.P. of Traction (Table) ....... 653 Horse Power of Traction (Table) 654 Traction (Table) 655 Revolution of Wheels for Various Speeds (Table) 655 Power for Double and Single Truck Cars (Table) 656 Tractive Effort on Grades (Table) 657 Kilowatts on Grades (Table) 657 Power Consumption, 25 M.P.H., 35-Ton Car (Table) 658 Number of Cars on Ten Miles of Track, Various Speeds and Head- ways (Table) 658 Effect of Shape of Moving Body on Air Resistance (Curves) .... Page Copper Wire Fuses for Railway Circuits (Table) 731 Approximate Dimensions of Electric Cars (Table) 732 Weight of Car Bodies and Trucks 734 Dimensions of Brill Cars (Table) 737 Electric Locomotives 739 Installation of Electric Car Motors 745 Preparation of the Car Body 745 Installing Controllers. 746 Wiring .... 746 Operation and Car? 3. Controller 747 Diagrams of Cat Wiring 747 Equipment Lists 752 Controllers 753 Series Parallel Controllers. 755 Electric Brake Controllers 755 Rheostatic Controllers 756 Dimensions of Controllers (Table) 757 Sprague G. E. Multiple Unit Control 761 Westinghouse Unit Switch Systems of Multiple Control 766 Approximate Rates of Depreciation on Electric Street Railways. 770 Depreciation of Street Railway Machinery and Equipment 770 Car Heating by Electricity 770 Track Return Circuit 771 Type of Bonds 772 Welded Joints 778 Resistance of Track Rails (Table) 779 Relative Value of Rails and Bonded Joints 780 Ingredients of Rails Under Test (Table) 780 Board of Trade Regulations for Great Britain 781 Calculation of the Overhead Conducting System of Electric Rail- ways 785 Continuous Current Feeders Load Determination 786 Economical Design of Feeders 786 Limiting Potential Drop 788 Two Classes of Feeders 788 Calculation of Dimensions of Conductors 791 Drop and Loss in Line Between Two Substations of Unequal Poten- tial 794 Impedance of Steel Rails to Alternating Current 795 Experimental Determination of Impedance of Steel Rails 795 Experiment on Inter works Track of W'estinghouse E. and M. Co. 796 Comparative A.C. and D.C. Resistance Trolley and Track per Mile of Circuit 798 Tests of Street Railway Circuits 798 Tests for Drop and Resistance in Overhead Lines and Returns. 798 To Read the (J round Return Drop Directly 799 To Determine Drop at End of Line 800 To Determine the Condition of Track Bonding and the Division of Return Current 800 TABLE OF CONTENTS. XX111 Page Testing Rail Bonds 801 Street Railway Motor Testing 803 Draw-Bar Pull and Efficiency Test without Removing Motor from Car 803 Testing Drop in Railway Circuits » ....... Destructive Effects 853 Increase of Current Flow upon Mains Due to Bonding same to Rails or to Negative Conductors 856 Current Movements upon Underground Mains 858 Electrolytic Effects upon Water Meters 855 Danger from Fire or Explosions 858 Electrolysis in Steel Frame Buildings 859 Current Swapping 859 Alternating Current Electrolysis 860 Insulating Joints in Mains 861 Surface Insulation 862 Summary 863 < ) XXiV TABLE OF CONTENTS. TRANSMISSION OF POWER, Page Engineering Features 864 Relative Efficiencies of Various Transmission Methods (Table) . . . 865 Special Features of Design Due to Transmission Line Requirements . 866 Motive Power 867 Storage Reservoirs 867 Generators 870 Transmitting Apparatus 870 Transformers 871 Pole Lines 871 STORAGE BATTERIES. Theory and General Characteristics 872 Voltage 874 Types of Plates 874 Capacity 874 Discharge Rate Curve 875 Voltage Variation 876 Electrolyte 877 Cadmium Test 878 Polarization 879 Efficiency 879 Comparison of Plante* and Pasted Electrodes . . 880 Charging 880 Removal from Service 881 Battery Troubles ". 881 Testing 882 Weight of Complete Cell and Component Parts , . . 882 Dimensions 883 Rates of Charge and Discharge 883 Capacity at Various Discharge Rates 883 Voltage Curves 883 Internal Virtual Resistance 883 Variation in Density of Electrolyte 884 Loss of Charge with Time . 884 Efficiency at Various Charge and Discharge Rates 884 Erection of Battery 884 Uses of Batteries 886 Methods of Controlling Discharge 889 End Cells and Switches 890 Counter E.M.F. Cells 891 Resistance Control 891 Shunt, Automatic, Reversible and Non-Reversible Boosters 891 Comparison of Boosters 897 Installations 897 Three-Wire Systems 899 Battery Capacity 900 Strength of Dilute Sulphuric Acid of Different Densities (Table) . . 904 TABLE OF CONTENTS. XXV Page Conducting Power of Dilute Sulphuric Acid of Different Strengths (Table) 905 Conducting Power of Acid and Saline Solutions . . ' 905 SWITCHBOARDS. Design of Direct-Control Panel Switchboards 906 Copper Bar Data (Table) 911 Aluminum Bar Data (Table) 911 Alternating-Current Switchboard Panels 912 Equipment of Single-Phase Feeder Panels 916 Equipment of Three-Phase Feeder Panels 917 Equipment of Two-Phase Feeder Panels 918 Equipment of Induction Motor Panels 918 Equipment of Three-Phase Synchronous Motor Panels 919 Equipment of Three-Phase Rotary Converter Panels 919 Equipment of Constant-Current Transformer Panels 922 Arc Switchboards 922 Direct-Current Switchboard Panels 924 Hand-Operated Remote-Control Switchboards . . 928 Central Station Electrically Operated Switchboards 928 Circumstances which Indicate the Necessity of Installing Electrically Operated Switchboard Apparatus 929 Hydro-Electric Generating Station Design 930 Bus-Bar and Bus-Bar Structures 933 General Arrangement of Switchboard Devices 935 Isolation of Conductors 936 Cells for Voltage Transformers 938 High -Tension Conductors 939 Controlling and Instrument Switchboard 940 Substation Switchboard Equipments 942 Switchboard Instruments and Meters 945 Method of Figuring Instrument Scales 946 Brief Guide for Writing Switchboard Specifications 947 Switching Devices . 948 Sparking at Switches 948 Circuit Breakers 949 Circuit Breaker Design 952 A.C. Service Circuit Breakers 952 Capacity of Circuit Breakers for D.C. Generators 955 Circuit Breaker Adapted for Motor of Given Size (Table) ...... 955 Signalling Relays 955 Regulating Relays 956 Protective Relays 956 Application of Relays 960 Lever Switches 963 Plug Tube Switches 965 Disconnecting Switches 965 Switches for High Potential 967 Westinghouse Oil Circuit Breakers 969 Oil Circuit Breaker Controller 975 General Electric Oil Switches 976 ( XXVI TABLE OF CONTENTS. LIGHTNING ARRESTERS. Page Lightning Protection 980 Switching 980 Cables 981 Engine or Water Wheel Governor Troubles 981 Protection Against Abnormally High Potentials on A.C. Circuits . . 981 Use of Reactive Coils 982 Use of a Protective Wire 982 Ground Connections 983 Lightning Arresters 983 Lightning Arresters for Direct Current 984 Lightning Arresters for Alternating Current 987 Non-Arcing Metal Lightning Arrester 989 Garton Arrester 990 S.K.C. Arrester 990 Static Discharges 992 Arresters for High Potential Circuits 993 Low Equivalent A.C. Lightning Arrester 994 Horn Type 995 ELECTRICITY METERS. Action of Integrating Meters 997 Direct-Current Commutator Type Meters 997 Thomson Recording Wattmeters 998 Westinghouse D.C. Integrating Meters 998 Duncan Meters 998 Induction Type Alternating Current Integrating Meters 999 Wattmeters on Inductive Circuits 1000 Power Factor Compensation 1002 Minimizing Effect of Voltage Variation 1002 Westinghouse Single-Phase Induction Wattmeters 1003 Westinghouse Polyphase Induction Wattmeters 1003 Thomson High Torque Single-Phase Induction Wattmeters .... 1005 Thomson Polyphase Induction Wattmeters 1005 Sangamo D.C. Integrating Meter 1006 Elementary Diagram of Sangamo D.C. Meter 1007  Testing 1013 Testing Service Meters 1015 Calibration Data for Westinghouse Integrating Wattmeters (Table) . 1016 Testing Meters for Accuracy on Inductive Loads 1018 Method of Testing Service Meter for Inductive Load Accuracy . . . 1019 Obtaining Inductive Load from Two-Phase Circuits 1019 Obtaining Inductive Load from Three-Phase Circuits 1020 Testing Meters 1020 TABLE OF CONTENTS. XXVli Page Testing Polyphase Meters 1020 Standards for Testing Polyphase Meters * 1020 Service Connections of Polyphase Meters 1023 Practical Methods of Checking Connections of Polyphase Meters . 1026 Meter Testing Formulae 1028 Formula for Testing the Shallenberger Ampere-Hour Meter .... 1028 Testing Formula for Shallenberger and Westinghouse Integrating Wattmeters 1028 Testing Constant of Westinghouse Meters 1029 Westinghouse Direct-Current Meters 1030 Table of Testing Constants for G. E. Co.'s Meters 1030 " D3 " Polyphase Meters 1031 Formula for Testing Duncan Recording Wattmeters 1031 Table of Duncan Constants " K " and Watts per Rev. per M. . . . 1031 Per cent Error Table for Fifths of a Second 1032 Table Values of Constants for Fort Wayne Single-Phase Meters . . 1033 Formula for Testing Sangamo Wattmeters 1035 Tables of Constants for Sangamo Wattmeters 1035 Graphic Recording Meters 1036 Bristol Recording Meters 1036 General Electric Graphic Recording Meters 1037 Westinghouse Graphic Recording Meters 1037 Action of Meters 1039 TELEGRAPHY. American or Closed Circuit Method 1040 European or Open Circuit Method 1040 Repeaters 1041 Milliken Repeater 1041 Ghegan Repeater 1042 Weiny-Phillips Repeater 1043 Duplex Telegraphy 1044 Duplex Loop System 1047 Half-Atkinson Repeater 1048 Duplex Repeater 1049 Stearns Duplex 1050 Quadruplex 1051 Telegraph Codes 1052 WIRELESS TELEGRAPHY. Electrical Oscillations 1055 Electromagnetic Waves 1055 Antenna 1058 Coherer 1058 Syntonic Signalling 1059 Skin Effect 1061 Transmitters 1062 Receivers 1064 Detectors 1066 Undamped Oscillations , 106£ I XXV111 TABLE OF CONTENTS. TELEPHONY. Page Receivers 1070 Transmitters 1071 Induction Coil . . . 1074 Hook Switch : . . . . 1075 Calling Apparatus 1075 Series and Bridging Systems 1076 Polarized Bell 1078 Construction of Magneto Generator 1076 Factors Affecting Transmission: Inductance, Capacity, Resistance . 1079 Earth Currents, Induction, Cross-Talk 1081 Metallic Circuits 1081 Open Wire Circuits 1082 Cables 1082 Sample Specification for Telephone Cables 1083 Capacity of Aerial Telephone Cables (Table) 1085 Capacity of Underground Telephone Cables (Table) 1086 Sizes of Cables (Table) 1086 Annual Expenses of Telephone Cables 1087 Lightning Arresters 1087 Classification of Telephone Lines 1088 Central Office 1089 Requirements of Satisfactory Operation of Switchboard 1089 Small Switchboards 1089 Multiple Switchboard 1090 Busy Test 1091 Series-Multiple Switchboard . « 1092 Branch Terminal or Bridging System 1093 Transfer Systems 1094 Relative Value of Multiple and Transfer Systems 1094 One Central Office vs. Several 1094 Trunking 1095 Method of Operating Circuit Trunks 1095 Auxiliary Trunk Signals 1096 Ring Down or Common Trunks 1096 Common Battery System , 1096 Rudimentary Common Battery Circuits 1097 Lamp Signals 1098 Circuits of Common Battery Switchboards 1098 Three- Wire System 1099 Two- Wire System 1101 Common Battery Instrument Circuits 1102 Party Lines 1102 Selective Systems 1102 Method of Obtaining Impulse Currents 1103 Central Office Apparatus Auxiliary 1104 Automatic Exchange Systems 1105 Simultaneous Use of Lines 1105 Limits of Telephonic Transmission 1107 TABLE OF CONTENTS. XXlX Page Notes on Cost of Telephone Plant 1108 Private Lines, Intercommunicating, and House Systems « . . . . 1108 Common Return Intercommunicating Systems 1114 Two-Wire Intercommunicating Telephone Systems 1120 USES OF ELECTRICITY IN THE UNITED STATES ARMY. Searchlights 1123 Data Relative to Searchlights (Table) 1127 Boulange* Chronograph 1128 Schultz Chronoscope 1130 Schmidt Chronograph 1131 Squire-Crehore Photo-Chronograph 1133 Manipulation of Coast-Defense Guns 1134 Electric Fuses 1134 Defensive Mines 1137 Fortress Telephones and Telegraphs 1140 Field Telephones and Telegraphs 1140 Telautograph 1141 Wireless Telegraphy 1145 Electric Ammunition Hoist with Automatic Safety Stop 1147 Night Sights . • 1148 Firing Mechanism for Rapid Fire Guns 1149 ELECTRICITY IN THE UNITED STATES NAVY. General Requirements 1154 Engine 1154 Typical Results of Tests on Generating Sets (Table) 1159 Specifications for Turbo-Generator Sets ... 1159 Turbine 1160 Generator 1161 Operation of Generator t 1162 Steam Piping 1163 Switchboards 1163 Double Dynamo Rooms 1166 Wiring Specifications 1167 Single Conductor (Table) 1169 Twin Conductor (Table) 1170 Methods of Installing Conductors 1170 Lighting System, Lamp Specifications 1171 U. S. Navy Standards for 100-120 Volt Lamps (Table) ....... 1176 U. S. Navy Standards for 200-250 Volt Lamps (Table) 1177 Valves for Navy Special Lamps (Table) 1178 Diving Lanterns 1179 Searchlights 1179 Signal Lights 1181 Ardois System 1181 Truck Lights 1181 Power System 1183 I XXX TABLE OF CONTENTS. Page Teste 1184 Principal Requirements for Controlling Panels 1185 Turret-Turning Gear 1187 Ammunition Hoists . . 1191 Endless Chain Ammunition Hoists 1192 Boat Cranes 1194 Deck Winches 1196 Ventilation Fans 1196 Water-Tight Doors 1198 Steering-Gear 1200 Interior Communication System 1202 Range Indicators 1204 Revolution Indicators 1204 Telephones 1206 Fire Alarms and Call Bells 1210 Range Finder 1211 Speed Recorder 1211 RESONANCE. Formula? for Alternating Current Flow 1217 THE ELECTRIC AUTOMOBILE. Resistance Due to Gravity and Power Required 1224 Resistance to Traction on Common Roads (Table) 1225 Tires 1225 Motors 1227 Batteries (Tables) 1227 Rules for Proper Care of Batteries 1228 ELECTROCHEMISTRY-ELECTROMETALLURGY. Electrolysis 1229 Resistances of Dilute Sulphuric Acid (Table) 1229 Resistances of Copper Sulphate (Table) "... 1231 Resistances of Zinc Sulphate (Table) 1231 Applications of Electrochemistry 1231 Electrolytic Chemistry 1231 Electrotyping 1233 Electroplating 1233 Electrolytic Refining of Copper 1235 Production of Aluminum 1239 Production of Caustic Soda 1239 Production of Metallic Sodium 1241 Potassium Chlorate 1242 Electrothermal Chemistry 1244 Calcium Carbide 1245 Manufacture of Graphite 1245 Electric Smelting 1247 TABLE OF CONTENTS. XXXI X-RAYS. Page Tubes 1249 Regenerative Tubes 1251 Exciting Source 1252 Interrupters 1253 Fluoroscopes 1255 ELECTRIC HEATING, COOKING AND WELDING. Various Methods of Utilizing the Heat Generated by the Electric Current (Table) 1256 Equivalent Values of Electrical and Mechanical Units (Table) . . . 1258 Cost of Electric Cooking 1259 Cost of Heating Water to Different Temperatures at Various Rates for Current (Table) 1259 Efficiency of Electric Cooking Apparatus 1260 Comparative Costs of Gas and Electric Cooking 1260 Comparison between Gas and Electric Rates 1261 Cost of Operating Electrically Heated Utensils (Table) 1261 Daily Electric Cooking Record for One Week (Table) 1262 Electric Irons for Domestic and Industrial Purposes 1263 Commercial Electric Laundry Equipment 1263 Electric Heating 1263 Radiators and Convecters 1263 Energy Consumption of Electric Heaters 1265 Comparison between Electric and Coal Heating 1265 Electric Car Heating 1265 Industrial Electric Heating 1269 Electric Heat in Printing Shops 1269 Soldering and Branding Irons 1270 Thawing Water Pipes 1271 Electric Welding and Forging • 1271 Electric Rail Welding 1273 Electric Smelting 1274 Annealing of Armor Plate 1274 Hydro-Electrothermic Systems 1274 Fuse Data * 1275 Tested Fuse Wire (Table) 1275 Installation of Fuses 1276 LIGHTNING CONDUCTORS. Selection and Installation of Rods 1278 Chimney Protection 1281 Tests of Lightning Rods 1282 Directions for Personal Safety During Thunder Storms 1283 Economy of Isolated Electric Plants (Tables) 1283 Data on Isolated Plants (Table) 1285 Data on Isolated Plants in Residences (Table) 1287 XXXii TABLE OF CONTENTS. MECHANICAL SECTION. FOUNDATIONS AND STRUCTURAL MATERIALS. Page Power Station Construction (Chart) 1289 Foundations 1290 Mortars 1293 Sand and Cement 1294 Weight of Flat Rolled Iron (Table) 1295 Weights of Square and Round Bars of Wrought Iron (Table) . . . 1297 Weight of Plate Iron (Table) 1298 U. S. Standard Gauge for Sheet and Plate Iron and Steel 1299 Columns, Pillars and Struts 1300 Strength of Materials 1301 Moment of Inertia 1302 Radius of Gyration 1303 Elements of Usual Sections (Table) . . 1303 Cast-iron Columns 1305 Transverse Strength 1308 Fundamental Formulae for Flexure of Beams 1308 General Formulae for Transverse Strength of Beams (Table) .... 1309 Approximate Greatest Safe Load on Steel Beams (Table) 1310 Beams of Uniform Strength Throughout Their Length 1312 Trenton Beams and Channels (Tables) 1313 Size and Distance between Floor Beams (Table) 1315 Properties of Timber (Table) 1316 Tests of American Woods (Table) 1317 Wooden Beams (Table) 1318 Southern Pine Data (Tables) 1320 Masonry 1322 Brick WTork (Tables) 1321 Weight of Round Bolt Copper (Table) 1323 Weight of Sheet and Bar Brass (Table) 1323 Composition of Rolled Brass (Table) ... 1323 Weight of Copper and Brass Wire and Plates (Table) 1324 Galvanized Iron Wire Rope (Table) 1325 Transmission or Haulage Rope (Table) 1325 Iron and Steel Hoisting Rope (Table) 1326 STEAM. Steam Boilers 1327 Types of Boilers 1327 Horse Power of Boilers 1327 Heating Surface of Boilers 1328 Grate Surface of Boilers 1329 Efficiency of Boilers 1329 Strength of Boiler Shells (Table) 1330 Rules Governing Boiler Inspection . 1332 TABLE OF CONTENTS. XXX111 Page Boiler Stays and Braces 1333 Boiler Settings 1334 Chimneys (Tables) 1338 Chimney Construction 1339 Blowers for Forced Draft 1344 Fans for Induced Draft 1345 Kinds and Ingredients of Fuels 1346 Total Heat of Combustion of Fuels 1347 Temperature of Fire (Table) 1349 American Woods (Table) 1349 American Coals (Table) 1350 Heating Value of Coals 1350 Anthracite Coal (Table) 1351 Bituminous Coal (Table) 1351 Approximate Analysis of Coal (Table) 1352 Analysis of Coke 1353 Space Required to Stow a Ton of Coal (Table) 1353 Weight of Coal (Table) 1354 Relative Values of Coals and How to Burn Them 1355 Wood as Fuel 1356 Liquid Fuels 1356 Chemical Composition of Petroleum Oils 1357 Comparative Costs of Oil and Coal (Table) 1358 Mechanical Stoking 1359 Water 1360 Weight of Wxater (Table) 1361 W^ater for Boiler Feed 1362 Solubilities of Scale-making Materials 1363 Purification of Feed Water by Boiling 1365 Table of Water Analysis 1366 Feed Pumps 1367 Pumping Hot Water 1367 Injectors 1370 Deliveries for Live Steam Injectors (Table) 1371 Rate of Flow of Water Through Pipes (Tables) 1373 Loss of Head Due to Bends 1374 Feed Water Heaters 1375 Saving by Heating Feed Water 1376 Pump Exhaust 1377 Fuel Economizers 1378 Steam Separators 1380 Safety Valves 1382 Rules for Conducting Boiler Tests 1384 Determination of Moisture in Steam 1394 Throttling Calorimeter 1394 Moisture in Steam (Table) 1396 Separating Calorimeter 1398 Quality of Steam Shown by Issuing Jet 1400 Factors for Evaporation (Table) ,. '. 1400 i XXXIV TABLE OF CONTENTS. 