Part 142

=Rainbow=, cause of, 253 colors in, what makes? 254 ends of, 254

=Rays=, change their course, 38 heat from light, 36 of light, 36 Roentgen, 307

=Rays-X=, what are they? 307

=Reason=, is there one for everything? 200

=Reed=, the (illus.), 12

=Reflection=, in mirror, 22, 91

=Refraction=, changing light rays called, 38 of light, 38

=Reproduction=, of life, in birds, 179 in fishes, 177 in plants, 175 why we must have, 174

=Rifle=, Kentucky, 45 kick of, 47 modern automatic, 47 over-loading, 47 wheel-lock (illus.), 46

=Rifling=, causes rotation of projectile, 32 a big gun (illus.), 60 of a gun, 53 invented in Austria, 46

=Roads=, concrete (illus.), 103

=Roentgen Rays=, 307

=Rope=, breaker (illus.), 360 compound laying machine (illus.), 361 cross-section, 362 draw frame (illus.), 360 drying fiber, 354 Egyptian kitchen (illus.), 354 Egyptians making (illus.), 353 preparing the fiber in (illus.), 359 four-strand (illus.), 362 hackling, 354 hemp (illus.), 356 hemp in warehouse (illus.), 356 knots, 363 lengths, standard, 362 oiling in manufacture, 356 long made by hand, 354 machine (illus.), 358 opening bales of fiber (illus.), 359 preparation room (illus.), 359 scraping fiber (illus.), 354 sliver formation of (illus.), 360 spindles, 355 spinning after turn, 355

=Rope spinning=, after turn, 355 foreturn, 355 splicing (illus.), 364 spreader (illus.), 360 stakes, 355

=Rope walk=, modern (illus.), 357-358 old-fashioned (illus.), 355

=Routine=, of a telephone call (illus.), 68

=Rubber=, automobile tires, 382 biscuit, 377 blisters, 379 blow holes, 379 breaker-strip, 384 calendering, 381 castilloa, 387 cement, 381 crude, 377-378 curing room, 382-383 dryer, 379 fabric, 384 furnishing pneumatic tires (illus.), 386 gathering (illus.), 377 how secured, 377 how are inner tubes made, 385 marketing balls of, 377 mixing, 379 Para, 387 pneumatic tires, 383 pure, why not used, 380 spreading, 381 spreader room (illus.), 383 tapping (illus.), 377 tire building machines (illus.), 385 tires, how made, 378-379-380 tread laying room, 384 tubes, inner, how made, 385 vulcanizing, 384 washing, 378 wild, what is, 387 why not used pure, 380 wrapping room, 386

=Rugs=, designs imitated by machinery, 168 Persian (illus.), 167 Persian, how made, 167 Persian, imitation, 167 Persian Kurdistan (illus.), 167 Persian, where best are made, 167 Tabriz, reproduction (illus.), 168 weaving by machine (illus.), 171

=Rug manufacturing=, carding machine (illus.), 170 examining and repairing (illus.), 173 packing for shipment (illus.), 173 processes, 169-170 weaving by machinery (illus.), 171 wool sorting, 170

=Sadness=, cause of tears, 38

=Salt=, beds, 493 chemical name of, 493 in water, 351 mines, 493 Salt Lake, 493 soda, 493 supply for United States, 493 wells, 493 where it comes from, 493

=Scales=, pressure of light on, 37

=School slates=, where they come from, 495

=Score=, origin of, 26

=Scouring=, wool (illus.), 85

=Scouring and weaving=, in making woolen cloth (illus.), 88

=Screens=, in shot tower, 51

=Sea=, diver, 202 how men go down to the bottom of, 202 navigating on bottom of, 283 time calculated on the, 315 what the bottom looks like, 202 what makes it roar, 401