Mechanical drawing. Elementary and advanced (1910)
Reid, John S. (John Simpson), 1856- · New York, J. Wiley & sons; [etc, etc.] · leaf 139
d the angle 4, 1, 3 is15°, and the proportion of the isometrical projection to theactual object is as the length of the line 3, 2 to the line 3, 4.And if the line 3, 2 be divided into any number of equal parts,and lines be drawn through these divisions par. to 2, 4 to cutthe line 3, 4 in… … Fig. 168. Since isometrical drawings may be made to any scale, wemay make the isometrical lines of the object = their true size.This is a common practice and precludes the need of a specialisometrical scale. The Direction of the Rays of Light.—The projection of aray of light in isometrical drawing…
