The original campus of the University of Michigan was nearly a perfect
square about a half-mile along a side. A street-sized walk,
appropriately called the Diag, runs diagonally across this square,
connecting its southeast and northwest corners. In 1904 a new
engineering building was either started or finished (I do not remember
which) to house classrooms. When another engineering building was built
on the expanded campus across the street from it many years later, the
old building came to be known as West Engine, to distinguish it from the
new East Engine. Old West Engine is (or maybe by now, was) a four-story,
L-shaped structure that stood at the southeast corner of the original
campus. It was built with an arch in it to straddle the Diag at the apex
of the L. You walked over the Engineering Arch to get from one leg of
the L to the other if you were inside the building, and you walked under
it when you entered the campus from the southeast corner. Affixed to the
masonry wall of the arch was a plaque I often noted in passing. It bore
a quote attributed to Horace Greeley (1811-1872), who I did not know at
the time was the founder, editor, and publisher of the New York Tribune.
It said, simply, Young man, when theory and practice differ, use your
horse sense. The suggestion seems worthy of an exclamation point instead
of a period, but I do not remember if it had one.