166. Projection is that department of geometrical drawing which treats of the drawing of elevations. plans, sections and perspective views. There are four kinds of projections, viz.: Orthographic, Isometrical, Cavalier and Perspective. Chapter III (Linear Drawing) is devoted to an explanation of the principles of orthographic projection.

Fig. 94.   Section of House on Line A B of Plan and Elevation.

Fig. 94. - Section of House on Line A B of Plan and Elevation.

167. An Elevation is a geometrical projection of a building or other object on a plane perpendicular to the horizon. (Pig. 92.)

168. A Plan is the representation of the parts as they would appear if cut by a horizontal plane. (Fig. 93.)

169. A Section is a view of the object as it would appear if cut in two by a given vertical or horizontal plane. (Fig. 94.) In the one case the resulting view is called a vertical section, and in the other a horizontal section. Oblique sections are representations of objects cat at various angles.

Fig. 95.   Perspective View of House.

Fig. 95. - Perspective View of House.

170. A Perspective is a representation of a building or other object upon a plane surface as it would appear if viewed from a particular point. (Fig. 9.5.)

171. A Detail Drawing or Working Drawing is a drawing, commonly full size, for the use of mechanics in constructing work.

172. A Scale Drawing is one made of some scale less than full size.

173. A Miter is a joint in a molding, or between two pieces not moldings, at any angle.

174. A Butt Miter is the term applied to the cut made upon the end of a molding to lit it against another molding or against a surface.

175. A Gable Miter is the name applied to the miter either at the peak or at the foot of the moldings of a gable or pediment.

176. A Rake Miter is a miter between two moldings, one of which has undergone a modification of profile to admit of the joint being made.

177. Square Miter is the common term for a joint at right angles, or at 90°.

178. An Octagon Miter is a miter joint between two sides of a regular octagon, or between any two pieces at an angle of 135°.

L79. An Inside Miter indicates a joint at an interior or re-entrant angle.

180. An Outside Miter is a joint at an exterior angle.

181. The Development of a surface is the process of finding, from a drawing of a rounded form, a shape or pattern upon a Bat surface which, when cut out and bent or formed as indicated by that drawing, will constitute its envelope; or, in other words, the stretching out flat of a surface shown by a drawing to be curved.

Alphabetical List

In the following list all words are arranged in alphabetical order, the figure following each referring to the number of the definition in the list preceding:

Abacus..................

138

Acute Angle...........

14

Altitude..................

35,100

Angle......................

12

Angle, Right............

13

Angle, Acute..............

14

Angle, Obtuse.............

15

Apex.........................

31

Arc............................

59

Arch..........................

120

Architrave................

118

Axis...........................

109

Base............................

32. 121, 124

Bed Course..................

145

Bed Moldings.................

144

Bracket...........................

130

Bracket Molding...........

149

Broken Pediment..............

126

Butt Miter........................

174

Capital..............................

138

Center.............................

54

Chord...........................

60

Circle............................

52

Circumference................

53

Circumscribed ........

66

Column ..............

121

Complement......................

69

Concave...........................

114

Concentric........................

64

Cone................................

94

Cone, Oblique or Scalene..

96

Cone, Truncated..................

97

Conic Section.........................

113

Convex..................................

115

Corbel.....................................

133

Cornice..................................

116

Co-Sine..................................

72

Co-Secant..............................

76

Co-Tangent............................

74

Crown Molding......................

142

Cube......................................

89

Cylinder, ................................

90

Cylinder. Elliptical........

91

Cylinder, Oblique.........

93

Cylinder, Right.....................

92

Decagon................................

48

Deck Cornice........................

129

Degree...................................

68

Dentil...................

132

Dential Course.....................

147

Detial Drawing.....................

171

Development...........................

181

Diagonal................................

51

Diameter................................

56

Die......................

124

Dodecagon............................

49

Dodecahedron....................

107

Drip ....................

155

Elevation..............................

167

Ellipse..................................

78

Elliptical Cylinder........

91

Engaged Column...................

121

Entablature..........

117

Envelope.......................

110

Evolute.........................

81

Eccentric......................

65

Fascia..........................

153

Fillet................

154

Finial..............................

137

Flange............................

164

Foot Molding................

148, 118

Frieze...........................

119

Frustum.........................

112

Gable..............................

127

Gable Miter.....................

175

Gable Molding........

150

Geometry............

1

Globe................

102

Head Block..........

134

Heptagon............

46

Hexagon ............

45

Hexahedron .........

105

Hip .................

165

Hip Molding.........

152

Hyperbola...........

80

Hypothenuse.........

30

Icosahedron ..........

108

Impost..........................

120

Incised Work.........

158

Inscribed.............

66, 67

Inside Miter..........

179

Intersection of Solids....

111

Involute.......................

82

Keystone.....................

120

Line.............................

4

Line, Curved................

6

Line, Horizontal..........

8

Line, Inclined or Oblique.........

10

Lines, Parallel........................

7

Line, Perpendicular...............

11

Line, Straight............

5

Line, Vertical........................

9

Lintel Cornice.......................

128

Lozenge............................

41

Miter................................

173

Modillion...........................

131

Modillion Course................

146

Molding.................

141

Neckmold............................

138

Normal Profile...........

163

Oblique Cone.........................

96

Oblique Cylinder..................

93

Obtuse Angle.......................

15

Octagon..............................

47

Octagon Miter.....................

178

Octahedron.......................

106

Outside Miter.....................

180

Panel....................

139

Parabola............................

79

Parallelogram.....................

39

Pedestal...............................

124

Pediment................

125

Pediment, Broken...................

126

Pentagon...............................

44

Perineter..................................

50

Perspective..............

170

Pilaster..................

123

Pinnacle.................................

136

Plan.....................

168

Planceer..................................

143

Plane ....................

17

Plane Figure...........................

20

Point....................

3

Polygon..................................

22

Polyhedron ..............

103

Prism ...................

84

Prism, Hexagonal........

88

Prism, Pentagonal........

87

Prism. Quadrangular......

86

Prism, Triangular........

85

Projection ...............

166

Pyramid.................................

98

Pyramid, Right...........

99

Quadrant................................

62

Quadrilateral ............

36

Radius.....................................

55

Rake....................

160

Rake Miter...............

176

Rake Moldings...........

160

Raked .Molding...........

161

Raked Profile.............

162

Rectangle................

42

Rectilinear Figure........

21

Rhomboid ...............

40

Rhombus ................

41

Ridge Molding...........

151

Right Angle..............

13

Right Cone...............

95

Right Cylinder...........

92

Right Line...............

5

Right Pyramid...........

99

Scale Drawing............

172

Scalene Conc.............

96

Scalene Triangle..........

26

Secant...................

75

Section...................................

169

Sector...................................

61

Segment...............................

58

Semicircle ...............

57

Shaft....................

121

Sides of a Triangle.......

33

Sink.....................

157

Sine.........................................

71

Slant Hight..............

101

Soffit....................

156

Solid....................

83

Sphere.....................................

102

Springing Line...........

120

Square ..................

43

Square Miter.............

177

Stay........................................

159

Stile.....................

139

Stilted...................

120

Stop Block................................

135

Supplement..............................

70

Surface...................................

16

Surface, Double Curved.. ......

19

Surface, Single Curved...............

18

Tangent....................................

63

Tangent of an Arc........

73

Tetrahedron .............

104

Trapezium...............

37

Trapezoid ...............

38

Triangle.................

23

Triangle, Acute-Angled. ..........

28

Triangle, Equilateral......

24

Triangle, Isosceles........

25

Triangle, Obtuse-Angled...........

29

Triangle, Right-Angled...........

27

Triangle. Scalene.........

26

Truncated Cone..........

97

Truncated Pyramid.......

97

Truss ...................

134

Versed Sine..............................

77

Vertex....................................

34

Volute...................

140

Voussoir ................

120

Working Drawing........

171