4
Hat. To Hang on a Lead Pencil 133
Hatpins, Sealing Wax, How to Make 175
Hats, Felt, Packing Cut from 207
Heat and Expansion 124
Heat, Cardboard Spiral Turned by 226
Heat, Experiment with 134
Heat Regulator, Electric 344
Hectograph, Homemade 240, 326
Hinge, Broom Holder Made of 33
Hinges, Imitation Fancy Wings on 224
Hinges, Leather, Metal Covering for 41
Hole, Square, How to Bore 179
Hole, Threaded, Sizing 295
Holes, Boring In Cork 8
Holes, Circular. Cutting In Thin Sheet Metal 35
Holes, Different Shaped, Fitting Plug in 122
Horn, Electric, How to Make 218
Horn, Paper Phonograph, How to Make 71
Horn Used as Funnel 7
Horsepower of Small Motors, Finding 238
House, Building In a Tree Top 146
Hydrogen Generator, Constant Pressure 70
Hydrogen Generator, Small Electrical 54
Hygrometer, How to Make 71, 140

I
Ice Boat, How to Build 357
Ice Boating 382
Ice, Bottle Pushing on 409
Ice Chisel, Handy 61
Ice, Fish Signal for Fishing through 10
Ice, Fishing through 281
Ice, Game Played on 216
Ice, Making a Fire with the Aid of 338
Ice, Merry-Go-Round Whirl on 380
Ice, Peculiar Properties of 100
Ice, Signals for Fishing through 380
Ice Skates, Hollow Grinding 231
Ice Yacht. How to Build 307
Illusion, Balloon Ascension 300
Illusion Box, Electric 135
Illusion for Window Attraction 239
Illusion. Miniature "Pepper's Ghost" 52
Illusion, Roller Coaster 293
Illusion, Rolling Uphill 361
Illusions, Optical 74, 99, 130, 183, 206, 348, 364
Incandescent Lamp, Experiment with 427
Indian Clubs, Weighting 318
Indicator, Electric, for a Wind Vane 348
Induction Call, How to Make 138
Induction Coil, Lighting an Incandescent Lamp with 112
Induction Call, Small Medical, How to Make 63
Induction Coils, Circuit Breaker for 101
Induction Calls. Mercury Make and Break Connections for 187
Induction Motor, Single Phase, How to Make 124
Ink Bottle Cork, Steel Pen Used in 117
Ink Spots, Removing 131
Inkstand, Ornamental Metal 315
Insulating Aluminum Wire 306
Insulating Cleats, Substitute for 348
Insulation, Removing from Wire 213
Interrupter, How to Make 51
Iodine Stains, Removing 425
Iron Castings, Putty for 269
Iron Flower Stand, Ornamental 353
Iron Polisher 286
Iron Rest for an Ironing Board 288
Iron Work, Ornamental, Easy Designs in 370
Ironing Board Stand, How to Make 17, 429
Irrigating with To