Euclid's parallel postulate: its nature, validity, and place in geometrical systems ..
John William Withers's 1905 study of Euclid's parallel postulate, published in Chicago by Open Court for mathematicians and philosophers of geometry. Line diagrams show labeled rays fanning from a point across a horizontal axis, and hatched triangles tiling a plane, offering designers clean geometric linework, lettered vertices, and repeating shaded tessellation patterns.
