INDEX TO VOLUME 88 



Page 



A Tuning-Coil Slider 468 



Reconstructing a Dry Battery 469 



Mounting Spark-Gaps to Elliminate Unnecessary 



Noise 471 



Winding Tuning-Coils 47 I 



What Radio Readers Want to Know 472 



Money Prizes tor Radio Articles 481 



An Undamped Wave Receiver 613 



The Tuning of Radio Telegraph Receivers 619 



How to Build the Mast for a Wireless 623 



What Radio Readers Want to Know 627 



How to Fit Cables Into Small Terminal Holes. . . . 762 



Damping in Radio Circuits 775 



A National Wireless Association 779 



Lamp Resistance for Charging Storage Batteries. . 781 



An Unusual Recording Receiver 782 



Tubular Quenched Gap 782 



Telephone Receivers 783 



Learning the Code 783 



Magnetic Adjustment of Audion 783 



An Electromagnetic Rectifier and a Polarized Relay 784 



Inexpensive Stranded Aerial Wire 785 



Automatic Dead-End Switch 785 



Audion of Increased Sensitiveness 787 



Repairing a Burnt-Out Fuse 788 



Constructing a Variable Condenser 787 



What Radio Readers Want to Know 790 



Sharpness of Tuning in Radio 935 



Antenna Wire Strength 940 



Preventing the Audion from Choking 943 



Unit Type of Plate Gap 943 



The Non-Synchronous Rotary Gap 944 



Quenched Gap Damping 944 



A Wireless Log for the Amateur 944 



Japanese Wireless Telephone 947 



Radio Tower at Tufts College 949 



What Radio Readers Want to Know 950 



RAILWAYS 



Locomotives Serve as Fire Engines 8 



Artificial Rainstorm Tests Car Roofs 10 



Sidewalk Shelters for the Trolley Patrons of 



Cincinnati 10 



Telephoning from a Moving Train 11 



A Boy's Wonderful Working Locomotive Model. . 25 



The Steam Engine in War 74 



Motor Car Mows Railroad Weeds 79 



Publishing a Paper Aboard a Train 185 



To Keep Automobiles Off Railroad Tracks 224 



The Size of a Railway Station 233 



New York Trains That Play Leap Frog 245 



Process for Painting Cars Rapidly 261 



Catching Eggs from Swiftly-Moving Trains 343 



Railroad Gate Warns and Stops Reckless Motorists 373 



Baking a Railroad Car to Dry the Paint 423 



Tamping Railroad Ballast with a New Air-Tool . . 536 



Stopping the Speeder with a New Danger Sign . . 541 



Not a Toy — A Real Locomotive 490 



Asleep on the Sleepers 688 



How Fast Is Your Train Moving? 693 



Burning Cars to Make Money 714 



How a Second-Hand Automobile Made a Railroad 



Pay. ... 732 



A Fire-Fighting Trolley Car 735 



A Scientifically Designed Train-Announcing Mega- 

 phone 741 



A Continuous Railway Crossing 745 



A Successful Railroad 828 



Expensive Transportation 890 



A Traveling Laboratory for Testing Railway Scales 890 



RECREATION 



Curved Spring Device Returns Bowling Balls. ... 813 



Ice Skating in Summer Without Ice 908 



Answers to Sam Loyd's April and May Puz- 

 zles 912 913 



Kite Making at Home 92 I 



A Camper's Dutch Oven 934 



ROAD BUILDING 



A Three Million Dollar Automobile Scenic Highway 56 



Perils of the Bad Road 226 



An Automobile Road Sign and a Map Combined. . 229 



Applying Hot Road Material 267 



Blasting for Good Roads 750 



Bad Roads Make Bad Going 829 



"Once Over" and the Road Is Done 876 



SHIPS AND SHIPPING Page 



New Diver's Suit Does Away with the Hand Pump 29 

 Gangway Life-Saver Prevents Crushing of Life 



Boats 58 



Gliding Boat for Tropical River Mail Service ... 74 

 Saving Men from Scalding Steam in Steamship 



Engine Rooms 254 



Detecting Fires in the Holds of Trans-Atlantic 



Liners 257 



Steamer Breaks Back in Storm 335 



A Submarine That Dived but Once 391 



The Unabashed Fish and the Noisy Motor Boat . . 393 



A Dreadnought's Buoy 404 



Floating a Sunken Warship on a Bubble of Air. . . 405 



Taming Those Harbor Pirates 498 



A Calking Compound 505 



Italians Build Highest Powered Motor Ship 541 



Breaking Storm Billows with Compressed Air ... 561 



The Undependable Fog-Horn 575 



Miniature Ships That Were Built to Prove a Point 580 



Reverses Tug's Propeller Blades 663 



Exit the Mississippi Stern- Wheeler: Enter the 



Motor Barge 696 



Making a Life-Saver of a Leak _ 700 



Using Triggers to Launch Uncle Sam's Battle-ships 703 

 Making Your Own Boat Repairs Under Water. . 711 



Submarine Signaling with Sound Waves 712 



Ancient Battleship Ideas Revived 737 



A New Way of Loading Steamers from Freight Cars 829 



SOUND RECORDING 

 AND TRANSMISSION 



Edison's Phonograph Diaphragm to Record Only 



Faint Sounds 10 



Selling by Show- Window Telephone 18 



A New Device for Recording Sounds 58 



Hearing the Stones on a River's Bed 92 



WAR PROBLEMS IN AMERICA 



Forts that Travel on Rails 323 



A Torpedo with Eyes 424 



Our Helpless Coast Defenses 499 



Helpless United States 689 



Undersea Fighting of the Future 803 



THE WAR AND ITS EFFECTS 



How War Mobilizes the Non-Combatant 812 



London War Affects Baby Carriages 812 



The Gentlest Bullet 819 



Marvelous War Map 828 



War and Trade 833 



How the War Is Being Fought 834 849 



WHAT'S NEW IN PATENTS 



Erasing Attachment for Typewriters 105 



Soda Fountain in a Suitcase . . 105 



A Finger-Knife for Egyptian Corn 105 



Foiling the Safe Blower ' I ' 



Baby's Bottle Holder I 58 



Tool for Stripping Insulation I 58 



Electrically Lighted Pencil 1 58 



Combined Door Bel! and Mail Receiver 1 58 



An Aid to the Veterinary 1 58 



A Room Stove Water Heater 1 58 



Sanitary Kneading Board '59 



Self-Feeding Soldering Iron '59 



A Pad and Pencil Holder for the Telephone 159 



Folding Tooth Brush I 59 



Apparatus for Cleaning Hair Brushes I 59 



Combination Sad-iron Heather and Cooking 



Utensil '59 



Shoe Polishing Device •(>0 



Opening and Closing Garbage Cans with the Foot . 160 



Purse in Palm of Glove 160 



Anti-Skidding Chain 160 



Walking Stick Becomes a Seat 160 



Meal-Holder Which Makes Slicing Easy 160 



New Headlight Dimmer 272 



Keeping Your Sole Warm 272 



Adjusting a Brush to Its Handle 272 



For Applying Chains to Wheels 272 



Combined Egg-Tester and Mailing Tube 272 



Clothes Rack Dryer 272 



Combined Coat Hanger and Trousers Stretcher. . . 273 



Making It F.asy for the Birds 273 



A Simple Signal for Automobiles 273 



