Practical draughtsmen's work, with numerous engravings and diagrams (1903)
Hasluck, Paul N. (Paul Nooncree), 1854-1931, ed · Philadelphia, D. McKay · leaf 49
Fig*. 68.—Parallel Lines Appear to Converge and to Diverge. … Fig. 69.—Square Partly CovereJ. paper at a distance of 3 in. centre to centre. Shut the right eye,and, with the left eye, look at the right-hand dot; on moving thepaper nearer or farther there will be found one position, whenthe eye is about 9 in. from the paper, at which the left-hand dotvanishes…
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from M. Vitrvvii viri svae professionis pertissimi De architectvra libri decem, ad Avgvstum Cæsarem accuratiss. conscripsit & nvnc primvm in Germania qva potuit diligentia excusi, atq[ue] hinc inde schematibus non iniucundis exornati (1543)](https://img.insideoutlibrary.com/img/200/ia-mvitrvviivirisva00vitr-259-90.webp)