Part 57

=Sloping Surface= in Projection desc. 159, illus. 166

=Solid=, def. 49, 83

=Solid Pattern=, def. 47

=Speed of Gears= 208

=Sphere=, def. 49

=Spiral Curve=, def. 44

=Spring Bows= illus. 122, 123, desc. 124

=Spur-Gear= desc. 201, illus. 211

=Spur Mortise-Wheel=, illus. 202

=Spur-Wheel=, desc. 199, 216 How to Draw 209 Illus. 198 Projection desc. 162, illus. 163 Teeth of cast-iron, desc. 202

=Square=, def. 48 To Convert into an Octagon 95 To Describe about a Circle 94 To Inscribe in a Circle 93

=Standards=, for U. S. 278 Office Rules for 193

=Steady Rest=, Scale, illus. 228

=Straight Line=, def. 46 To Draw a Perpendicular to a 86 Drawing Figures of 66-7-8 How to Draw a 57, 59 To Bisect a 86

=Steel=, Section-Lining, illus. 182

=Steel Gears=, Economy of 216

=Surface=, def. 49, 82

=Symbols=, representing Materials 193

=Table= of Areas of Circles 273-277 Bolts, Standard Sizes of 280 Circular Measure 272 Circumferences of Circles 273-277 Contents 24 Decimal Equivalents 269 Diameters of Circles 273-277 Land Measure 272 Metric Equivalents 270 Pipe, Standard Sizes of Welded 279 Roman Figures 272 Solid Measure 272 Wire Gauges 278 Useful for Draughtsmen 266-280

=Tangent= of an Arc, def. 99 To Draw a, to a Circle 91

=Tee-Iron=, illus. 75

=Tee-Square=, Adjustable, desc. and illus. 113 Desc. 112 How to Use, illus. 111, 147 Illus. 102, 112 Points about 242

=Teeth in Bevel Gears=, desc. 204

=Terms and Definitions=, Preliminary 41

=Test-Pieces=, Use of, in Blue Prints 188

=Tetrahedron=, def. 48

=Theorem=, def. 83

=Thumb-Tack= illus. 109, desc. 110