Appleton's dictionary of machines, mechanics, engine-work, and engineering (1869)
New York, Appleton · leaf 533
:ipal pro] ■ uhi h out e ich other, nn I il tal. | :m I the plan of projection is a plane which touches I •• 526 PROVING MACHINE, HYDROSTATIC. point of contact is called the principal point; and the projections of all other points on the sphere areut the extremities of the tangents of the arcs…
Mechanical engineering
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
