Page:Popular Science Monthly Volume 89.djvu/13

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.



Cardboard Tubes 275

How a Compact Molded Condenser Is Built 275

Primary Regulator for the Induction Coil 275

Small Radio Stations 275

Lowering t^e Decrement 277

Lighting Audion Bulbs Cheaply 276

Music by Wireless 278

A Substitute for An Aerial 280

Telephone Headbands 280

A Built-Up Wireless Mast 281

A Sending Condenser 282

Adjusting Handles 283

A New Detector Material 284

A Good Loose-Coupler Switch 285

Modified Audion Is New Telephone 285

Reducing Arcing at Key Contacts 285

A Quencned Gap with Metal Spacers 286

Switch Points for Radio Instruments 286

What Radio Readers Want to Know 287

A Microphonic Amplifier 437-

Constructing an Amateur's Aerial 439

Guying the Mast 442

A New Tuner Arrangement 445

Lepel Improves His System 445

A New Variable Condenser . . .• 448

The Quenched Gap 448

A Kick-Back Preventer 448

How to Become a Wireless Operator 449

Curious Form of Dustproof Detector Cup 452

A Rotary Adjustment for Coupling 452

What Radio Readers Want to Know 453

Insulating the Ground Connection in Radio Work 613 An Easily Made Self-Locking Device for Barn-

Doors 614

Converting a Plain Zinc-Gap into an Air Blast

Spark-Gap 62 I

Strengthening the Static Field of an Amplifier. . . , 622 Overcoming Troubles in a 200-Mcter Wave Outfit 623

How to Become a Wireless Operator 627

Employing Kites to Support an Aerial 630

A New Spark-Gap for Wireless Telephony 63 I

Making a Crystal Detector from Cheap Materials 633 Wireless Telegraph Stations in the West Indies . . 633 I ns'ilating and Decorative Enamel for Electro- Magnets 634

Best Wavelengths for Certain Distances 635

What Radio Readers Want to Know 636-637

Converting a Freight Car into a Wireless Station. 639

The Construction of a One-Mile Receiver 789

How to Become a Wireless Operator 789

Making an Inductance Switch for Radio Work. . . 796

What Radio Readers Want to Know 797

Simple Method of Remagnetizing Magnets 799

The Telephone Receiver for Wireless Apparatus. . 799 Experiments with Antennas of Varying Lengths. . 800 Making the Aeroplane Generate Its Own Power

for Wireless 842

Using a Tree as a Mast for a Wireless Station .... 871

Making an Emergency Aerial for Wireless 948

How to Become a Wireless Operator 949

Transformer Trouble in Radio Transmitting

Apparatus 954

Practicing the Code Without Using a Buzzer 955

How to Take Up the Slack on Your Aerial Wires. 955 Canada to Protect Her Parks with Radio Service. 955 Preventing Interference of Signals by Amplifying. 956 A New Direct-Current Transmitter in Radio

Communication 957

What Radio Readers Want to Know 958


End-Door Automobile Express Cars 7

Driving Railway Spikes with a Motor-Car 26

Hairpin Curves on a Mountain Trolley Line 48

Beautifying- Manhattan's Riverfront 86

Minute Men of the Rails 169

Boy's Road Wagon Is u Real Locomotive 183

An Auto Mountain Railway 207

A Western Railroad's Clay Locomotives 242

A Railroad Which Fights Its Own Fires 251

The Senators' Subway 328

A Locomotive that Burns Pulverized Coal 376

Feeling the Way 379

Railroad Treads for Motor-Trucks 391

Stopping Trains Automatically 433

Odd Uses for Railroad Cars 500-501

Solving New York's Freight Problem 546


Ten Millions to Save Four Miles 553

A Danger Signal Which Compels Attention 572

Our First Armored Car 588

The Hose Is Mightier Than the Brush 688

A Motor-Wheel for the Railroad Velocipede 742

A Locomotive Side-Frame Which Weighs Nearly.

Seven Tons 829

A Wind- Deflecting Lookout Mask for Engineers. . 832

Daylight Lamp Signals 847

A Device for Adjusting the Ends of Steel Rails. . . 915 Transforming a Railroad Water-Tank Into a

Home for Two 919


Protecting a Battleship with a Belt of Air 18

How a Steamer's Engine Room Is Ventilated .... 104

Charting the Dangers of the Deep 204

Coaling a Liner with An Elevator 206

The World's Largest Ships' Register 226

Pulverized Coal Burners on Our Modern Ocean

Steamships 230

A Damaged Lock Gate Repaired by I ts Own

Water 234

A Venetian Barge in Boston 258

A Guard for Mooring Ropes to Prevent Rats from

Landing 363

Tethering the Largest of the Super-Dreadnoughts 381 Milazzo — the Largest Coal Ship in the World. . . 392

Cooling a Ship's Laundry 477

Pocket-Flashlight Distress-Signals 520

Piping Oil to Ships at Sea 521

A Fog-Stick for Traffic on the Great Lakes 522

A Fleet of Indoor Battleships 578

Detecting Enemy Submarines from a Ship's Look-

Out 579

Preventing Ships from Rolling with Fly Wheels . . 592

The Thousand-Foot Battleship 670

A Novel Device for Generating Fresh Air in Sub- marines 681

Telegraphing Through the Ocean 711

Defending America with Motor Torpedo Boats. . . 721

Miniature Magnet-Propelled Ships 737

Discovering Contraband of War 752

An Endless-Chain Barge Loader 845

She Lies on Her Side— But They'll Raise Her 880


Doing Without the Caddy 12

Golfing at Home 13

Playing Baseball by Machine 57

The Five-Wheeled Velocipede 64

What Ho! The Jitney Yacht 83

A "Jackomobile" for Two 100

What Inventors Are Doing for the Fisherman . . . 105

Camp Fire Maxims ....T 115

Kite Making at Home — II 127

How to Make a Practical Gas-Range Lighter .... 156

Weightmobile Approaches Perpetual Motion 158

Leaping Horses That Are Unafraid 168

Another Baseball Game in Disguise I 74

An Air-Tight Compartment for Canoe Campers. . 184

Turning Your Racket Press Into a Camp Stool . . . 224

The Latest in Golf Clubs 246

"Canal Boats" Which Are Real Water-Shoes... 257

The First Bird House Ejthibit 260

Making a Bomb Thrower for Sham Battles 295

The Whistling Bicycle Wheel 297

How to Make a Toy Zeppelin 313

Ferreting out the Secrets of the Golf Ball 324

A Metal Disk Supplants the Golfer's Tee 324

Golfing by the Clock — a New Idea for Golf Courses 325

What Golfing Sometimes Does to the Feet 325

Making Your Head Behave While You Hit the Ball 325

A Paddleless Canoe Propelled by Feet and Hands 326

Mechanical Joys of Coney Island 394

Playing Checkers on the Lawn 398

Good-By to the Pin-Boys in the Bowling- Alley . . . 409

Battle Ball— a New Sport 420

Getting Ready for the Clay Birds 421

A Fascinating Old Sport in a New Dress 436

The Trench Marble Game and How It Is Played. . 455

Decoy Ducks That Quack and Swim 509

The Old Fondness for Cycling Is Coming Back. . . 514

Hunting the Mud Pigeon 530

Bucking a Wooden Football Line 554

Playing Ball with a Revolving Fan as a Target . . 568

Motoring on Rollcr-Skates 569

�� �