Jacob staff, use

Congrats on the find Nate!?ÿ I know you've wanted one for a while.

Thanks!

There's a place down some 40 miles away from me called "magnet cove".

You have to have a compass, to work this area.

As the name implies, it's got "disturbances".

Thanks,

Nate

Be careful with that thing. See pages 44 and 45 here:?ÿ

https://www.google.com/books/edition/Surveys_and_Surveyors_of_the_Public_Doma/y98lAAAAMAAJ?hl=en&gbpv=1&dq=jacob%27s+staff+surveying&pg=PA45&printsec=frontcover

I just can't wrap my head around finding a Jacob's Staff in a Thrift Store, wow.

The best thing I ever found is a nearly mint condition stainless steel stove top percolator.

Having never seen a Jacob's staff demonstrated, I have a hard time visualizing how you get one to be stable enough in the ground.

It seems like the soil would either be too hard to get it planted or too soft to keep it in place.

@bill93

In times past it wasn't uncommon to "stack a sight"..meaning placing a plumbed range pole at a point so the instrument would have a reliable back sight for transit work.?ÿ Getting one to stay plumb in the ground at a point was a real art.?ÿ It always reminded me of attempting to climbing a pole.

I'm sure placing a Jacob's Staff is a similar exercise.?ÿ With all the wallering and twisting required I'm sure there were some that didn't survive.?ÿ Funny thing is that I have destroyed a number of aluminum range poles over the years.?ÿ But I still have a set of antique wooden poles (4' sections) that actually survived.?ÿ I couldn't tell you if they're hickory or bois d'arc, but they're a tough hardwood and look similar to the wood in photos of compass staffs.?ÿ?ÿ

I've never used a Jacob's staff in the field, though I did make one out of a hoe handle just in case I ever get around to playing with the staff compass I have.?ÿ But I *was* concerned about being able to stick it securely enough in hard or rocky ground until I realized that I can just clamp a bipod on it.

The only times I've run compass lines for realz was on a USFS job many years ago.?ÿ We used a Brunton on the little Brunton aluminum tripod.?ÿ That tripod isn't very robust, but it works fine if you're careful not to bend the legs.

I used a Jacob's Staff once a LONG time ago (~50 years) to run a Forest Trail "ROW" with the USFS. I had a ~6" Compass and a 100' rag tape (3-man crew) and was NOT impressed with the Jacob's Staff. I rifed through the equipment locker that weekend and found a [very] light weight wood tripod that was designed for use with a compass of that type, and never looked back (or used the Jacob's Staff again). When using GOOD procedures (solid setup & fore and aft reading at each setup), one can get reasonable results. When retracing old compass surveys, this is really the hot setup (especially if you are getting Total Station or GPS shots on the turns [PIs]). Over the years I have used a Brunton Compass w/ the aluminum Brunton Tripod quite a bit for this purpose, but the LARGER format Staff Compass is much better than the small Brunton format.?ÿ

In my limited experience, using a Jacob's Staff was similar to using a ROD with a prism or GPS receiver attached WITHOUT any reliable way to keep it "steady." The Compass of course had a fish-eye bubble, but you couldn't really see what the bubble was doing while sighting through the Compass. I never tried to "STICK" it in the ground because the Uinta Mountains were/are pretty much solid rock! Traversing through a moist meadow would of course be a different proposition. A NON-MAGNETIC bipod should work pretty well, but we didn't have such things 50 years ago (bear in mind though, most bipods have steel springs and other parts that can screw with the compass readings).

In my opinion, using a Transit with a ~4' diameter compass, and reading the compass fore and aft (measuring angles with the Transit scope & vernier) is the best way to go (with GPS readings if possible).

Loyal?ÿ

Thanks Loyal.

I was in soil, when I tried mine out. I'd remove the compass/adaptor. Jab the staff, until it was stable. Then add the compass/adaptor. Then use the ball joint to level it. Then, loosen the lower part, that allows the compass to stay level, rotate it, and use it. I assume a user could use a hammer, and sharp stake to make a pilot hole, in hard soil. I did testing after very little rain. Soil was quite hard. The pilot hole method would be a necessity, in many areas. It was marginal, for needing a pilot hole, when I did it.

We are loosing the people who remember, at a fast rate.

I started with 1923 A Lietz transit.?ÿ

Lietz tm20c theodolite, with K&E autoranger.

Topcon gts 3c

Locus gps. Topcon rtk, and Javad LS RTK.

Will this be my last gear? Probably not.?ÿ

I really wonder where the persons STARTING now, with rtk, RTPK, etc will end up!

I know my grandpa, never dreamed of EDM'S. I wonder. Will we get millimeter rtk, in the deep dark woods someday? Probably. It's fast approaching now. In less than 5 mins per shot?

Probably. It's nearly here now. MM gps is here now, out in the open. Centimeter GPS in the woods is here now.?ÿ

I think every new licensee should traverse around 40 acres with compass and chain. Then, transit and tape. Then total station. Then with modern gps. Both RTK, and Post Processed. On each trip around, set the 10 acre corners. Then study all the data, and thoroughly analyze it.

Professionalism involves knowing "when to hold 'em", and when to pincushion 'em. (Disturbed mons get pincushioned, usually).

Recently, another surveyor found one of my monuments, in the deep woods. It was 0.11' from where he had computed to set it. It's getting better, but we are all in a state of perpetual growth. Me too.

Thank you all for participating in this thread.?ÿ

Nate

@nate-the-surveyor

Maybe we should have a field practicum added to the FS and PS exams to validate examinees.

Id be all for that. And the pee behind the tree lab would be mandatory too.

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I've used a Jacob's staff in Forest with no detectable local magnetic attraction.?ÿ The soil (deep duff on top of easy dig soil) was easy enough that I just jammed it in like a vertical javelin then put the compass on it.?ÿ It is stable enough for the accuracy of a compass survey.?ÿ Naturally in areas with very hard or rocky ground that wouldn't work well.