Johnston, Philip Devereux, 1855- · New York, D. Williams Company · leaf 74
/3IB F,c. 23 … Fts. Z^ 60 70 A MANUAL OF MECHANICAL DRAWING. In Plate i6 is given a practical application of theapproximate spiral drawn from four centres. Thisdrawing shows the case of a blower. The centres fromwhich the outer curve is drawn are 4 apart, 2 eachside of the centre line of the blower case. The…
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Cours d'architecture enseigné dans l'Academie royale d'architecture : premiere[-cinquième] partie ... (1675)](https://img.insideoutlibrary.com/img/200/ia-coursdarchitectu00blon-110-54.webp)
