In the late 1960s I bought two military Bruntons from Ft. Hood. I think Bill Russell got them at $3 or $4 each for us. They were in mils of course, but I surveyed many caves with them. I just got some trig tables in mils and no problem using a slide rule to reduce data. One had a plain compass needle, the other had a self-damping plate under the needle that made it settle down quickly, and I liked that one more. Used mirror and shadow methods both, and mostly hand-held, but I glued some brass strips on the sides of one of them to accommodate a Brunton clamp for a tripod. One of those Bruntons is now in the TSS museum. Used a lot in Mexico, Texas, and New Mexico. I got a Suunto compass and clinometer about 1973.and stopped using Bruntons. The Brunton clinometer was difficult to use and Suunto was an improvment, especially for handheld surveys.
In the 1990s I ran a calibration test course on the surface during our big Powell's Cave resurvey project. The surveyors brought old Suuntos and a new one. The compasses disagreed overall by about 2°, sometimes >5°. And a new Suunto was the worst one of the lot, so age of instrument was not a good predictor. I had a Suunto clinometer that began to stick after years of use, and the readings became unreliable, so I got a new one. Lang Brod used to demonstrate how he checked a compass on a rotating, lazy-Susan table, with maybe 5° increments. A compass can have bad spots and good spots all the way around. I've also "swung" an airplane compass a few times when I owned an airplane. Even with compensation screws, you have to calibrate, then fill out a correction card for 12 directions at 30° apart. Most air compasses can be off by 0 to 5° in any direction, so the card tells you what to steer for a correct course. The compass card is mounted right on the compass. Very important. Also important for cave surveys, but few cavers have ever done even a rudimentary test. We tend to confuse precision (trying to read to 1/2°) with accuracy. All of this is pretty much academic when surveying a smaller cave with one set of instruments. Good sketching and a good GPS location are more important in my opinion. Some people should not sketch, and they generally don't. Have fun with your old Bruntons! I still own one that works, and a couple of worn-out Suuntos. *William R. (Bill) Elliott* *speodes...@gmail.com <speodes...@gmail.com>* 573-291-5093 cell On Tue, Jul 23, 2019 at 1:07 PM Pete Lindsley <caverp...@gmail.com> wrote: > DIsto X2s are great in a cave when they are calibrated. I have modified 6 > units so far with 2 more on the bench. One of those I suspect has a bad > daughterboard. I found out the other Disto had an issue before I took it > apart. It helps to calibrate the units before going into a cave. At Stanton > we have found bad calibrations both during a survey or afterwards. Ditto > for Bruntons & Suuntos. So you need to be able to calibrate the DIsto X2 in > the cave, which means you need to carry in your Android phone or tablet. > (The Brunton is more rugged than those smart devices, and may be a worthy > backup unit.) > > All of the Suuntos I have bought have only lasted for 3-4 years before you > have to replace the clouded up “smart part”, at just slightly less cost > than a brand new Suunto. The Suuntos can also have compass & inclination > errors (like Disto & Bruntons) but few people bother to check calibration. > At least the Suuntos are waterproof. Suuntos & Bruntons work well in the > daylight, not so much the Distos. > > For the Disto units where the laser does not align with the sides of the > unit, you certainly need to carefully run a calibration that rotates the > unit on all 4 sides. Some of the calibration videos out there don’t do that. > > I started off with a used tripod-mounted quadrant Brunton using the Shadow > Method. We ran the closure data in Carlsbad against Tom Rohr’s theodolite > and precision level survey using the Hardy-Corcoran Fortran program on an > IBM 360. Overkill for your smaller caves, but we made pretty good FS/BS > measurements out to ~ 100 feet. Over the last 15+ years the Fort Stanton > Snowy River surveys have used all of these devices and our sketching > techniques have improved 200%, partially because it is so easy to use the > Disto to accurately shoot in the key sketched items. The Suuntos apparently > introduced blunders, and perhaps lazy FS/BS techniques, because some of > those older surveys appear to show that water runs uphill. > > Our new trick is an Arduino controlled data logging barometer that we hope > will help sort out these past elevation errors. I am hoping we can kill off > some of our 20 foot elevation closure errors from old Suunto surveys with > the baro units quickly checking the route. When your 12 mile long stream > passage has an average inclination of ~0.2 degrees, careful backsights > become very important. It might even help to mount your Disto-X2 on a > tripod and take instrument height / light height data like we were doing 50 > years ago with the lowly Brunton. Hand-held 200 foot Disto shots usually > have quite a bit of “wiggle” if you are trying for 0.5 degree precision. > > - Pete > > On Jul 23, 2019, at 8:07 AM, John Brooks <john.brooks.archit...@gmail.com> > wrote: > > IMO - the Brunton can stay on the collection shelves....I remember > numerous survey trips with Pete using his favorite Brunton....one trip he > called a string of alien sounding numbers and quadrants.....after > scratching my head for a few minutes....I asked him to translate it into > “English”. I think he converted every shot afterwards.....after the trip I > politely suggested that a suntos compass might be easier....I don’t think > Pete ever agreed and just kept using The Brunton. > > Sent from my iPhone > > On Jul 22, 2019, at 6:18 PM, JamesJasek <caver...@hot.rr.com> wrote: > > Sure would be good to go back to those days > > Sent from my iPhoneX > > On Jul 22, 2019, at 5:53 PM, Charles Loving <lovingi...@gmail.com> wrote: > > Tape and Brunton survey by...... I recall those in early days before > Bockbeer and his telenovela. > > On Mon, Jul 22, 2019 at 12:12 AM Pete Lindsley <caverp...@gmail.com> > wrote: > >> Logan, I bought a Brass Brunton several years ago off eBay, and the >> seller claimed it was an authentic antique. NOT! It is a lower >> precision “look alike”, made in India along with similar artsy transits and >> the like. As I recall, comparing it to the other 3-4 “real” Bruntons I >> have, I noted around 30 differences with an authentic Brunton. Nice to look >> at, but not a precision instrument. It took about a month to get my money >> back (~$30-40). >> >> - Pete >> >> On Jul 21, 2019, at 11:00 PM, Logan <lmcn...@austin.rr.com> wrote: >> >> I'm interrupting the TexasLockLearList to discuss something that actually >> has relevance to caving, and to Lee Jay Graves RIP. >> >> The caving connection is the Brunton Pocket Transit, aka the Brunton >> Compass. >> Except for the old-timers, most of you probably have never used one, so >> here is some background from Wikipedia. >> https://en.wikipedia.org/wiki/Brunton_compass >> It was commonly used by cavers when I started in Fall 1968. >> >> But over the next several years it had been largely replaced (at least >> among the American cavers I knew) by the Suunto compass made in Finland, >> which are still popular today. >> https://www.suunto.com/en-us/About-Suunto/History-Timeline/ >> In fact for quite a few years a set of the compass and clinometer has >> been donated by TSS to the winner of the TCR Survey Contest. >> >> Now the Lee Jay connection: His storage shed needs to be empty by July >> 31, so Justin Shaw assembled a team with Galen Falgot, Drew Thompson, Eric >> Flint & Meg, and Logan McNatt to go over there Friday July 19th evening. >> Gil Ediger loaned his wonderful Isuzu dump truck and we spent several hours >> loading over half the contents of the shed. Early the next morning we >> unloaded everything onto tables in Gil's front yard for an "Everything Must >> Go Fire Sale". >> >> As we emptied the tubs and bags, I noticed something I had never seen >> before: a *Brass* Brunton Pocket Transit, in pristine never-used >> condition! So I removed it from the sale items thinking it can go in the >> Texas Speleological Center Museum whenever that is transferred from the old >> TSS office at the Pickle Research Campus. A Google search showed the image >> below which is identical except Lee Jay's is stamped with INDIA rather than >> STANLEY LONDON. It appears to be functional and probably modern. At least >> it doesn't say "Made in China"! >> >> Comments and more information on this item are most welcome. Please >> forward to other cavers who might have insight. >> Thanks, >> Logan McNatt >> >> >> >> [image: Image result for Brass Brunton compass India] >> >> >> END OF INTERRUPTION; RESUME "USUAL" PROGRAMING ON TEXASLOCKLEARLIST >> >> >> >> _______________________________________________ >> Texascavers mailing list | http://texascavers.com >> Texascavers@texascavers.com | Archives: >> http://www.mail-archive.com/texascavers@texascavers.com/ >> http://lists.texascavers.com/listinfo/texascavers >> > > > -- > Charlie Loving > _______________________________________________ > Texascavers mailing list | http://texascavers.com > Texascavers@texascavers.com | Archives: > http://www.mail-archive.com/texascavers@texascavers.com/ > http://lists.texascavers.com/listinfo/texascavers > > _______________________________________________ > Texascavers mailing list | http://texascavers.com > Texascavers@texascavers.com | Archives: > http://www.mail-archive.com/texascavers@texascavers.com/ > http://lists.texascavers.com/listinfo/texascavers > > _______________________________________________ > Texascavers mailing list | http://texascavers.com > Texascavers@texascavers.com | Archives: > http://www.mail-archive.com/texascavers@texascavers.com/ > http://lists.texascavers.com/listinfo/texascavers > > _______________________________________________ > Texascavers mailing list | http://texascavers.com > Texascavers@texascavers.com | Archives: > http://www.mail-archive.com/texascavers@texascavers.com/ > http://lists.texascavers.com/listinfo/texascavers >
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