Elementary Descriptive GeometryUniversity of California. May, 1917 - 266 pages |
Common terms and phrases
30 degrees 45 degrees angle of 30 angle of 45 axis thru AXONOMETRIC PROJECTION base parallel center of vision circle cone construct the shadow coordinate plane cube cylinder degrees with GL degrees with H Descriptive Geometry diagonal diameter distance Draw the projections equal Find the intersection find the projections find the shadow Find the true foreshortened front view frustum ground line H plane H projection H-pr hence hexagonal isometric drawing isometric lines isometric projection jection line parallel Mechanical Drawing middle visual ray object oblique projection orthographic projection parallel to H passing thru perpen perpendicular to H picture plane plane of projection PLATE Prob projections of points projectors pyramid ray of light revolve the card revolved thru shown in Fig shows the shadow side view slant height straight line surface third quadrant thru an angle thru the point tion top view true length V-pr vanishing points vertical projection
Popular passages
Page 44 - ... give the perspective representation of an OCTAGON. By drawing diameters midway between those already drawn on the plan, eight other points in the curve may be found. This would give sixteen points in the curve, and render the operation of tracing much more correct. NOTE 2. — A CIRCLE in perspective may be considered as a polygon of an infinite number of sides, or as a figure composed of an infinite number of points, and as any point in the curve may be found, it follows that every point may...
Page 95 - ... cutting off Medusa's head. Among the latest works of art which deal with Perseus are a series of designs by. Mr. BurneJones. Perseus is easily recognisable in artistic representations as he carries the Gorgon's head and a curved sword, and wears wings on his heels and head, Perspective. Perspective is the art of representing upon a plane surface objects as they appear to the eye of the spectator from one fixed point. — , JErial. The art of indicating the relative distances of objects by means...
Page 85 - ... edges or axes, make equal angles with the plane of projection, and are therefore foreshortened equally.
Page 30 - Cz,Dz, shows in its true length and the line CD itself may be considered as lying in the plane of the paper. The line CE has one end CL in the plane of the paper while the line itself really slants down below the paper. The true size of the angle which it makes with the plane of the paper is equal to the angle EpCpFp.
Page 24 - ... in recent years there has been a tendency on the part of some companies to resort to questionable advertising practices.
Page 86 - CG the same length. As each edge of the cube is parallel to one or the other of these isometric lines, the drawing m.-.y be completod as shown.
Page 58 - ... tersecting: in geom., the point or line in which two lines or planes cut each other. Interjetant, in- té r- sí 'kan t, adj., dividing into Parts ; crossing. Intcripene, in-tcr-spers', v,i., todisperse Gt sprinkle among; to set here and there :~pr.p. interspers'ing;/a./. interspersed'.
Page 30 - ... actual length of the line. 5th. If a line is oblique to either coordinate plane, its projection on that plane will be shorter than the actual length of the line itself. 6th. If a line is parallel to one coordinate plane and oblique to the other, its projection on the plane to which it is parallel is equal to the true length of the line in space, and the angle which this projection makes with the ground line is equal to the true size of the angle the line in space makes with the plane to which...
Page 105 - The student should reriember that the correct lettering of every point and line, and the observance of the character of lines, is as much a part of the solution of the problem as is the correct location of a point ot line.
Page 114 - Thickness of material .?-". The long edges of the box are parallel to H and make an angle 'of 30 degrees with Y.