Part 146

=Talking machines=, 490

=Target=, floating, 31 Never seen by men firing mortar, 29 projectile, arrival at, 24

=Tears=, caused by onions, 38 as an eye-wash, 38 run along channel, 38 where they come from, 94 where they go, 94

=Teeth=, why they are called wisdom, 125 why they chatter, 218

=Telegram=, how it gets there, 414 story in a, 412

=Telegraph=, cables (illus.), 424 code, 419 calling a messenger, 414 waiting calls (illus.), 414 arrival at destination (illus.), 417 duplex, 417 electric, 420 electric, first suggestion of, 420 inventor of, 420 two men inventors of, 421 instruments, 425 instruments, first sending (illus.), 426 instrument, sending, 418 key, modern (illus.), 427 key, a later, 427 key, sending (illus.), 418 line, first, 422 messenger receives message (illus.), 415 messages, number sent in a day, 417 multiplex, 417 operating room (illus.), 423 the pony (illus.), 413 quadruple, 417 Wheatstone, receiver (illus.), 425 Wheatstone sender (illus.), 425 receiving operator (illus.), 416 relay, the first (illus.), 426 relay, modern (illus.), 427 recording apparatus first (illus.), 426 recording instrument improved, (illus.), 427 repeater room (illus.), 424 sending operator (illus.), 416 sounder, modern (illus.), 427 main switchboard (illus.), 423 automatic typewriter (illus.), 425

=Telephone=, apparatus, 65 birthplace of (illus.), 70 cost of number in use (illus.), 77 display board (illus.), 65 discovery of, 71 feeding cable into duct (illus.), 76 first outdoor demonstration, 75 how an emperor saved the, 73 forces behind your, 77 modern distributing frame (illus.), 75 line, the first, 72 line lamp, 66 pilot lamp, 66 from bottom of ocean, 203 operator, 67 breaking up the asphalt pavement (illus.), 76 a cable trouble (illus.), 76 call routine of (illus.), 68 beginning of service, 75 the first switchboard, 72 laying multiple duct subway (illus.), 76 first practical commercial test of telephone, 75 how wires are put underground (illus.), 76 nine million in use, 75 the first words over, 74

=Tens=, counting in, 19

=Test=, of big gun (illus.), 53

=Testing=, materials and products in gun factory (illus.), 50 artillery instruments, 24

=Tests=, shooting (illus.), 48

=Things=, to know about a big gun, 53

=Throats=, making sounds with our, 78

=Thread=, silk, made uniform (illus.), 120

=Thunder=, why it precedes lighting, 140 does it sour milk? 196

=Tickled=, why we laugh when, 93

=Tides=, where does water go at, low, 219

=Time=, age of clocks, 391 blacksmith’s clock (illus.), 320 first modern clock, 319 hour-glass (illus.), 317 time-boy of India (illus.), 317 where the day changes, 325 where is the hour changed? 325 clock in Independence Hall (illus.), 323 clock in New York City Hall (illus.), 323 largest clock in the world, 321 machinery which runs a big clock (illus.), 322 how man measured, 314 modern clock, description of (illus.), 319 primitive twelve-hour clock, 318 water clocks for, 317 water-clock (illus.), 318 man’s first divisions of, 314 what it is, 313 three great steps in measuring, 316 first methods of telling (illus.), 313 in New Testament, 314 sun-dial (illus.), 315 sun-dial in determining noon, 316 calculated at sea, 315 tower of the winds (illus.), 318 how told when sun casts no shadows, 317

=Tin=, why used for cooking utensils, 267

=Tobacco=, barn, 515 growing crop, care of, 514 growing under cheesecloth (illus.), 512 grown in Cuba, 513 cultivation of, 516 curing of, 515 cigars, how made, 517 how discovered, 512 field (illus.), 515 figures about, 519 filler, 518 fertilization, 514 where it comes from, 512 shade growing, 517 where does it grow, 512 harvesting, 515 Havana, where grown, 513 origin of name, 512 planting, 514 seed beds, 514 first care in selection, 518 strippers, 518 bulk sweating, 516 wrappers, 518 butter worm, 514

=Toes=, why we have ten, 142

=Toothache=, what good can come from? 410 cause of, 410

=Torches=, used in battles, 44

=Tow-line=, of floating target, 31

=Trains=, why harder to stop than start, 223

=Transparent=, why some things are, 350

=Trees=, found in coal, 261

=Tube=, of a gun, 54