century old survey technique

You need eight place log tables to reduce the trig back then.

Oh . . Right! of course. I completely forgot logs. We only spent one day on those because the instructor said it was obsolete. By then slide rules had already been replaced by calculators.

Thanks!

Yes they are obsolete now, but were quite popular in 1908!

Never use a slide rule to reduce survey notes. Always measure the angle six times when using a one minute transit (don't forget to divide by six). Make sure your steel tape is calibrated and adjust for temperature.

I'll think of some more rules of thumb after my nap!

Those engineers of long ago may have been old, but they were clever.

I am a bit of a student of history of technology for the industries I have worked in; I suspect many of the posters on this site are also. I used to work in Research in "byproduct cokemaking" for a steel company for some time. At one point I succeeded in mathematically modeling the byproduct process recovery train for a generalized coke plant model using available software from the ASPEN (Advanced Simulation for Process Engineering) Project developed at MIT. As I conducted the study using records, data and texts from the mid-1800's through the 1930's, I learned that the "old masters" who originally developed the process were very clever individuals. The often lacked the tools (eg:computers, etc) we now have at our disposal, but they engineered around the problems and forced things to work.

In one fairly standard operation of such a plant, I learned the importance of "brute force" engineering solutions. Those units were much over-designed based on what we now might consider to be necessary, but often the lack of good data, etc. made it necessary for those engineers to over-design. Interestingly, that over-design saved them, as it has since been demonstrated to be necessary.

Interesting bit of History.

Amazing what could and had been done in the past.

Exactly my thoughts. As I drive around the mountains and river valleys of BC I am awestruck at the daunting challenge of mapping a total wilderness that these guys faced. How did they know to go round the mountain this way rather than the other way? I was taught celestial navigation using a sextant in the Navy, but I'm still impressed at the land surveyor's ability to accurately fix their position when placing their principal tiangulation point. Most of them only had a pocket or fob watch not a much more precise and rated marine chronometer. I have been involved in both land and hydrographic survey work but we always had the benefit of starting from a known bench mark to begin with.

I Too could say:"Exactly my thoughts, But obviously not from the Strong Foundation & Experience you have." I was reminded of a summer job, earthmoving for two reverse curves, in hilly territory. The Owner was a older Scandanavian, who had cut & supplied the Railroad with Pine Ties & Long Timbers for the Bridge over the Sask.River in 1931. Now the job we were on, the Engineer got delayed, until we hadn't any staking to follow. After waiting One whole day, The Boss said to me, bring Your sharp axe, we'll cut Poplar Stakes & do our own staking. When the Engineer came, there was 1/2 mile of curves with a 38 ft. fill over a creek, where there had been no staking. As Mad as that Engineer should have been, It only Produced a Lot of Swedish Slang, and two days of Surveying, Only to prove it was all where the Original Prints showed it should be. Than the Engineer said to the Boss: "Why did you not tell us you Had Engineers Papers in the Old Country?" His brief Reply:" Ya vell I only used what I learned, before I Quit School. " "So what education have You Got?" "I went to Grade 4." He proved a few times, His Understanding Of Our High School Geo-Trig was better than ours. Now Many times, I've wished I could have spent more time by his side, before being asked to be his Paul Bearer, at his Funeral. Have a geat day. Carl.

Great story Carl! Confirms my own feeling we have gone soft from easy living. I remember when I first read about Total Stations from Hewlett Packard cost a years salary. Dang! It would have been so much easier if we had the use of that kind of equipment. As I drive by some survey crews lately, I notice many of them look bored. Guess making the job easier hasn't done much for making it more interesting and challenging.

I picked up a survey theodolite at the flea market for $80. It was brand new in 1964. Has all the newest options we never had when I first did construction surveys as a summer job in around 1965 and '66. We would have killed to have such neat equipment. <grin> Imagine getting all four corners of a lot from a single set-up! And eliminating all that chain work.

The guy I bought the thedolite from was a retired surveyor. The instrument had been calibrated most recently about 3 years prior. He told me tales of doing geologic surveys for mining companies in northern BC. Not much of that going on anymore.

These days, boat navigators rely to much on electronics. Don't even bother with a magnetic compass. If the electrons ever leaked out, they would be totally lost. Haven't got a clue how to go back to basic principles. Somehow I don't think modern education is what it should be.

Hi elnav,

maybe this will help:

http://en.wikipedia.org/wiki/Leveling_instrument

regards,

S

For Elnav, & Carl. I cut my teeth in the 1970's using some books that were huge, at least 10" x 14", with calculations to 25 places to the right of the decimal, and used calculators made by an electric typewriter company when I was in a local community college. Hewlett Packard would come out with the first hand held calculator with full trig functions in about 1975. I was in school from 1971-73. I remember having to "wait my turn" for the trig books to do my survey reduction and closure notes.

We had one instance where we kept coming into an area done by one of the original land surveyors, but we had a heck of a time finding the heal marks on the bearing or witness trees of the corners that he had established, until by pure dumb luck we met the old boys great grandson, and when he told us that Gramps was almost a 7 footer, it really began to make sense as to why none of the trees that we found seemed to have any heal marks. We were stubbies, 6' and under, so after we adjusted our "diameter at breast height" we re-visited some of the trees and found heal marks at his particular chest height. He also did a lot of celestial readings for his points of beginnings on some of his surveys, and these were in the 1850's here in Oregon, USA.

Interesting times,..and ringing true to a photographer's retort when he asked what I done for a living at the time, when I told him that I worked for the local County Surveyor's office,.."Oh, I remember,...wet ass, cold feet, runny nose, picnic everyday!" That kid called it right on the nail head. There are some of those old trig books still around, I have one that is better than 70 years old from an old friend. Thanks for your post, and have fun.

When I was a student (in sixties) there was no calculator, xerox, fax etc., As a matter of fact even the chip was not invented. We used a slide rule & T square - an engineer's trademark for centuries. Civil engineers used 7 figure tables, both trigonometric & logarithm. Jig boring operators also used them along with solution of triangles. Present generation of engineers unfortunately have 'no time' to learn these; it is not necessary to practise them.

Of course the technological advancement has made skill redundant - die & mould making, as well as pattern making have become cheaper and faster with cnc machines. The development costs & time have come down drastically. Everything from cars to computers, cellphones & air travel have become affordable to the middle class.

Still engineers should take an interst in history of technology