Duncan Hall is laid out on a regular grid of columns,
separated by eighteen feet, eight inches.
The grid can be seen clearly as the lines on the
first floor plan.
The column centers always line up on the grid line.
When a corridor runs through the column line, the
corridor is centered on the grid line of the hypostyle.
Notice that the spacing of the hypostyle is altered by
the double-bubble column (at grid lines 12 & 13, counting
from the left).
This lets gridline 4, the east edge of the western arcade,
line up with
the face of Abercrombie Lab while leaving the central
axis of Martel Hall (the midpoint between grid lines
15 & 16) aligned with the centerline of the Lovett Hall