PREFACE
During a discussion conducted at a meeting of the Herbert M. Evans History of Science Club, early in 1968,[3]
where I
reported on my findings on the scale and construction methods used in the Plan of St. Gall, Professors Charles L. Camp
and Hunter Dupree drew attention to the striking similarity between the series 640, 160, 40, 10 and 2½, used by the designer
of the Plan in laying out the primary area divisions of his monastery site[4]
and the measurement system embodied in the
American Land Ordinance of 1785.
The latter is familiar to anyone reared on the great western plains or wherever in the vast territory of the Midwestern
United States that land division into sections one mile square, each composed of 640 acres (fig. 539), is quite visible
Internally these are divided into half-sections of 320 acres, quarter-sections of 160 acres, and downward by the same
process of binary division into parcels of 80, 40, 20, 10, 5, and 2½. In the great rural plains of America, as it was subsequently
pointed out by Hunter Dupree, the expression "the back forty" and "the front forty" (for divisions of a section)
or "forty acres and a mule" (to define subsistence, if not plenty) are deeply imbedded in American history and in common
usage even today.[5]
These analogies raised the interesting question whether the American land measuring system of 1785 might be historically
connected with the system used in the Plan of St. Gall. The problem has since become the subject of two fascinating
studies by Hunter Dupree, the first entitled "The Pace of Measurement from Rome to America," published in the Smithsonian
Journal of History, III, 1968, 19-40, a second and more extensive one entitled "Measure is the Measure of All
Things," read at the Annual Meeting of the Society of the History of Technology, in Washington D.C. on Dec. 28, 1969;
and a third, "The English System for Measuring Fields," Agricultural History XLV:2 (1971), 121-29.
The historical implications of these three studies of Prof. Dupree's are vast and arresting. After brilliant beginnings in
the earlier parts of the nineteenth century, the history of mensuration has fallen into a state of almost complete stagnation.
That my work on the Plan of St. Gall should have inspired Hunter Dupree to stir new life into this subject adds a new
dimension to the Plan of St. Gall and heightens my excitement about my own findings.
I am grateful to Hunter Dupree for allowing me to include in this work a summary from his own pen of those aspects
of his studies which cast light specifically on the historical significance of the Plan of St. Gall as a connecting link between
earlier and later measurement systems. His report is rendered verbatim.
