Untitled, which hangs in the Barker Engineering Library, was made in 1968. Its sinuous curves are derived from the artists explorations of minimal surfaces to generate sculptural form. (Minimal surfaces are the most economical connections between loops or lines in three-dimensional space.) The sculptures bright metal edges correspond to the circles in space that generate the complex forms, in contrast to the textured white of the painted surfaces. Engman wrote (letter to Patricia Fuller, July 29, 2009) of its making: That particular piece started off essentially with three interlocking circles along a major axis. Each of the circles is 120 degrees from one another along that axis and rotates 120 degrees from each other. Each of these circles intersects the other two, approximately one third of the diameter of each circle. Along that axis halfway the length of the three circles, is a fourth circle perpendicular to that axis and in the center of the configuration. After these four spatial limits were established along that axis, I developed four minimal surfaces dictated by these limits and assembled them as such. The interesting thing for me about this stuff is that it is not in its final form a minimal surfaced configuration but rather an assemblage of four minimal surfaced configurations which are identical and which become united and continuous by a fifth central minimal configuration joining the four previous minimal surfaced configurations. Its interesting because there is no other way that this final form can be arrived at. I have had it pointed out to me that these forms cannot be conceived of within the field of mathematics. They can be described mathematically after they have been arrived at but they cannot be conceived of through any other system than that of the giving of substance to thought.