Part 143

=Second=, reckoning in millionths of a, 25 pictures taken in one five-thousandth of a, 31

=Seeds=, why plants produce, 175

=Seeing=, why we cannot see in dark, 91

=Sensation=, of sight, 22

=Sensitive=, paper, 23

=Service=, military, U. S., 24

=Shadows=, cause of, 495

=Shell=, sounds in a, 79

=Shells=, filling with powder, 50 inspection of metallic (illus.), 49 putting metal heads on paper, 50 wad-paper in making, 50

=Sheep=, coming out of forest (illus.), 82 first in America, 80 fleece packing, 82 how much wool does a sheep produce? 83 how wool is taken from the, 82 how taken care of, 82 how we get wool off of, 82 industry in America, 80 industry in the colonies, 81 industry in the west, 81 number in the west, 81 shearing, 82 shearing machines, 82 wool-producing, 83 why sheep precede the plow in civilizing a country, 81

=Shield driving=, air lock bulkhead (illus.), 210 caulking the joints (illus.), 214 description of airlocks, 213 erector at work (illus.), 214 erector (illus.), 210 at end of journey (illus.), 216 grommetting the bolts (illus.), 214 grouting (illus.), 214 how it cuts in tunnel building, 212 how they meet exactly (illus.), 215 in tunnel building (illus.), 208 key plate (illus.), 214 curves around (illus.), 216 models of Penna. R.R. tunnel shields (illus.), 212 rear end in tunnel building (illus.), 210 tunnels, front view (illus.), 209

=Ship=, how does a captain steer his, 407 how can it sail under water? 269

=Shoes=, Amazeen skiving machine, 550 assembling machine (illus.), 552 automatic heel loading and attaching machine (illus.), 560 automatic leveling machine (illus.), 559 automatic sewing machine, 555 American made, 547 ancient and modern forms of sandals, (illus.), 543 ancient sandal maker (illus.), 541 beginning of a shoe (illus.), 549 boot developed from the sandal, 544 boots (illus.), 546 channel cementing machine (illus.), 558 channel laying machine (illus.), 559 channel opening machine (illus.), 558 Crakrow or peaked (illus.), 544 which church and law forbade (illus.), 544 description of ancient sandal (illus.), 542 dyeing out machine, 551 different parts come together, 551 duplex eyeletting machine, 550 edge trimming machine (illus.), 560 Ensign lacing machine, 551 evolution cf the sandal to the shoe (illus.), 542 first machine for making shoes, 545 hand method lasting machine (illus.), 553 heel breasting machine (illus.), 560 heel trimming machine (illus.), 560 ideal clicking machine, 550 Inseam trimming machine (illus.), 556 insole tacking, 551 lasting machine (illus.), 553 loose nailing machine (illus.), 559 success of McKay machine, 547 machine that forms and drives tacks, 554 machines which punch the soles of, 559 my lady’s slippers (illus.), 548 placing shank and filling bottom, 556 planet rounding machine, 551 power tip press, 550 pulling over machine (illus.), 552 putting the ground cork and rubber cement in, 556 rolling machine, 551 rounding and channelling machine (illus.), 557 sewing the sole on, 558 slugging machine (illus.), 560 sole laying machine (illus.), 557 Summit splitting machine, 551 upper stapling machine (illus.), 554 upper trimming machine (illus.), 554 welt and turned shoe machine (illus.), 555 welt beating and washing machine, 556 welt sewing machine, 551 what was the first foot covering like? 541 “whipping the cat,” 545 who made the first shoe in America? 545 work performed by heeling machine (illus.), 560

=Shooting tests= (illus.), 48

=Shotguns=, assembling of, (illus.), 48

=Shot pellets=, 51

=Shrinking=, pit for big gun, 59

=Shuttle=, In weaving wool, 86

=Siberian lambs=, in South Dakota (illus.), 80

=Signs=, talking by, 18

=Silica=, mine (illus.), 247

=Silk=, 109 called “bomby-kia,” 110 caring for young worms, 113 culture, 110 drying skeins of, 119 dyeing, 121 first step in manufacture, 119 first used, 109 hatching eggs, 113 introduction of into Europe (illus.), 110 number of cocoons in pound of, 117 manufacture of, 119 method of reeling, 113 moths depositing eggs (illus.), 112 preparing cocooning beds, 112 reeling silk from cocoon (illus.), 118 spinning (illus.), 120 thread made uniform (illus.), 120 threads ready for the weaver, 121 twisting (illus.), 120 use of, 109 water-stretcher (illus.), 121 winding (illus.), 119

=Silk manufacture=, doubling frames, 120 spinning, 120 twisting, 120

=Silk moth=, description of 114

=Silkworm=, age, 115 first breeder of, 109 chrysalis (illus.), 114 cocoon, 115 cocoon, beginning of (illus.), 116 cocooning bed (illus.), 112 description of, 114 domestication of, 111 eating (illus.), 115 female moth (illus.), 114 how cared for, 113 how it eats, 115 home of, 112 eggs, how imported, 111 hatching the eggs (illus.), 113 how he does his work, 114 larvæ of, (illus.), 114 motions of head in spinning, 115 molting season, 115 moths emerging from cocoon (illus.), 117 male moth (illus.), 114 mulberry branches for (illus.), 112 one of the world’s greatest wonders, 116 preparing for making cocoon (illus.), 116 reared, how they (illus.), 115 shedding old skin, 115 spinneret of the, 115 spinning cocoon, 115 wild, 109

=Silver=, definition of, 207 use, history of, 207 why does it tarnish, 266

=Silver bromide=, in photography, 23

=Skins=, used for clothing, 80