University of Waterloo, Waterloo, Ontario: 16mm.
"To develop a single auxiliary view of a line, enclose it with vertical, horizontal, and profile planes. Project the line onto the three planes, remove it, and join the coordinates of the end points of the projected lines. Open the cube, flattening it onto a two dimensional surface to show the bearing—the angle of the line from north. An auxiliary view can then be made by rotating the angle of the profile plane until it parallels the line as viewed from the horizontal plane. This will show both the line in true length and the true angle between it and the horizontal plane. If the profile plane is rotated until parallel to the vertical view, the resulting auxiliary view will show the line in true length and the true angle between the line and the vertical plane."