Surveying
Joseph Mansfield

Dear Jim,

My first visit to your place in Española was in 1996. I drove out with John. This was while Jim Hall was working with you.

The order of business at that time included finishing the main drain of the house. When I arrived the drain had already been constructed above ground, a trench had been cut, and it remained to get the assembled structure into the trench. We did that with a rope contraption that I worked out. But before lowering the drain we had to make one final check on the slope of the trench. You had a transit or a level set up for the purpose. In passing, you asked me if I knew surveying. I said I was not up on surveying per se, but that I did know trigonometry, which was the soul of the thing, so I understood what was being done.

What I did not say, not out loud anyway, was that surveying had always interested me, and that I felt deficient in not knowing more about it. And further, that I resolved to remedy my ignorance some day.

Over the past several weeks I have fulfilled my resolution. I read a book simply titled Surveying, by Charles Breed. It was a textbook from the 1940s issued as Education Manual 908 by the United States Armed Forces Institute (USAFI) at Madison, Wisconsin. The book has 580 pages (95 of them math tables) and 253 figures. As this text is intended for soldiers studying by correspondence, a section is included on building simple, but workable, surveying instruments, for those who otherwise have no access to such equipment.

I had had no idea of just how extensive was the need for surveying, used for digging a coal mine, measuring a coal pile, and everything in between. But here I will just comment on two applications that interested me most.

The first is the layout of curves in railways and high speed highways – basically arcs tangent to two straight and intersecting lines, but with special features, possibly pieces of a spiral, to ease a vehicle into the arc and then ease out of it. Who would have thought there was that much to a curve? It also had never occurred to me that the same situation is treated in a “vertical curve”, where the grade of ascent or descent changes. And there must be a lot more to be said, for the thirty or so pages dedicated to curves end with a footnote referring the reader who wants more to a whole big book just about curves.

I did want a bit more than what the present book has, for it does not comment on crowns or banks. The words are not even mentioned. I am now more curious than ever about the mathematics of getting into and out of a banked curve. How twist the cross section of a straight to meet that of a curve? Maybe I will have to read some of that advanced book on curves. This is something I get to thinking about on long drives. Need to know more about it.

The other part that interested me was the thirty-five page chapter on the great land survey of the western United States. In principle the survey was not a complicated thing. But to contemplate the magnitude of it, and the problems to be overcome and the hardships to be endured! Dust storms, rattlesnakes, freezing winds! Points falling in lakes, tree trunks, inaccessible cliffs! And all according to a plan drawn up 226 years ago and hardly modified since. No writer could ever write a western novel so exciting, or so moving.

What about the Armed Forces Institute? It was a magnificent thing, a great correspondence school, whose nominal purpose was to enable soldiers nearing discharge and having only military skills to acquire some knowledge of civilian skills or trades before entering the civilian job market. But in practice there was no restriction to those ending their service. Any soldier could take any course at any time, for no more reason than that it interested him. Fees were nominal to the point of being negligible. I believe the Institute also served recently discharged veterans.

The present text on surveying was published during WWII, so we know the Institute was operating then. It was also operating in the late 1960s, for I was in the Signal Corps at that time and I recall looking into it. I have always been fascinated by telephone systems. The Institute offered a course in “dial central offices” and I meant to sign up for it, just for my own edification. But I never did.

A few weeks ago I went online looking for USAFI. I thought I might redeem my intention of learning about telephony just as I was redeeming that of learning about surveying. But I did not find the Institute, and I barely found any evidence that it ever existed. Perhaps some great soul has in fact written a comprehensive history of the Institute and I just failed to find it. But I doubt it. It appears the Institute has disappeared, hardly leaving a trace in the sand.

All best to you,
Joseph

*     *     *

From 1980 until 1982 I attended the legendary Episcopal parish, “The Church of Our Saviour”, in Atlanta. This was during the tenure of the even more legendary rector, Father Roy Pettway, known internationally for his extreme conservative politics as much as for his showcase High Church parish. It was at Our Saviour that I met Jim Sturrock, to whom I have remained close ever since.

I will tell just one story about Jim. The parish in those days served supper on Sunday nights. Those who planned to eat were asked to sign a reservation sheet not later than noon. One weekend I needed to see Jim about something. He was not at church on Sunday morning, but I noted that he was signed up for supper and figured I would see him then. Well, he was not at supper either. When I mentioned this later he advised me that he had had to cancel and had scratched out his name on the list. But his normal handwriting was itself so much of a scratch that I had not noticed the cancellation.

Discloure: This is an essay in form of a letter, not an actual letter that was mailed.

© 2010 Joseph Mansfield. All rights reserved.
2010.11.03 First draft
2010.11.04 Revisions
2010.11.05 Posted



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