crawlers, 10, 48, 49 crowd shovel, 49 “cub” tractor, 44 cultivator, 21 cutter heads, 15 cutting head, 81 cyclone, 39 derrick, 69 Diesel engine, 47 dipper, 49 “dogging,” 52 dredges, 14-15 driller, 72 driverless plow, 32-35 earth mover, 58 egg machinery, 24 egg sorter, 24 electro-magnet, 84 escalators, 83-84 farm machines, 18-45 giraffe, 83 go-devil, 77-78 gooseneck trailer, 48 grader, 61-64 grass planter, 26 harrow, 18 hay baler, 26-27 hay blower, 67 hay rake, 27 hay stacker, 28-29 heater, 53 hoe, compressed air, 36, 37 “hot-dope gang,” 74 house, 49 house moving, 58 jackhammers, 12 jib, 52 joint, 70 lumbering machinery, 85-86 magnet crane, 84 “making hole,” 72 manure scoop, 24 mechanical mouse, 89 milking machine, 29-32 mining, machinery 78-83 motor grader, 61-64, 67 motor scraper, 57 mowing machine, 26 Muskeg schooner, 69 nut harvester, 41 oil wells, 69-74 ore unloaders, 84 overhead crane, 10 “package job,” 22 piggy-back crane, 10 pile driver, 13 pipelines, 74-78 plow, 17, 18, 32, 33, 34, 35 post-hole digger, 16 potato digger, 42 powder monkey, 60 power shovel, 47-48 pull-shovel, 49 pumps, 78-80 reaper, 22, 42 rig, 70 ripper, 61 rivet gun, 53 rivet man, 53 road building machines, 55-68 rock crusher, 12 rock rake, 60 rotary rig, 72 rotolactor, 30-32 roughnecks, 72 scraper, 61 seed planter, 67 shovel, 9, 47-48, 49 signals, 52, 84, 88 silage blower, 26 skull cracker, 54 snow plow, 45, 67 spraying machines, 38-39 spud, 15 squeezer, 89 steam engines, 80 steam roller, 66 steam shovel, 47-48 suction dredge, 57 tandem roller, 65 tassel picker, 40-41 television, 88, 89 “thinking machines,” 89 tomato planter, 22 tongs, 70 tractor, 17, 18, 44, 45, 58, 61 trailer houses, 69 tree-dozer, 17 tree-shaker, 41 trencher, 74-77 turntable, 51 turtle, 89 two-gang plow, 18 vacuum unloaders, 84 welding crew, 74 well drilling, 69-74 wheat planting machine, 22 windrower, 27 wrecker, 54 [Illustration] The author and the artist wish to thank the following for their help in making this book possible: Miss Elsie Eaves, Manager, Business News Department, _Engineering News-Record_; Margaret Gossett; Mr. Harold Spitzer; _The Lamp_, published by the Standard Oil Company (New Jersey); the Caterpillar Corp.; the General Motors Corp., the New Jersey Bell Telephone Co.; the Florida Land Clearing Equipment Co.; the Walker-Gordon Laboratory Co.; the many manufacturers of digging, road-building and other specialized machines; a bumper crop of tractor and farm implement makers; and farmer friends who proudly showed their equipment in action. * * * * * $1.50 MACHINES AT WORK _By_ Mary Elting _Illustrated by_ Laszlo Roth