Old Benchmark Found

[+RampagerBOH]

After my first day of geocaching, I found this old benchmark near the bay while walking home.

 

 

This wasn't found on the geocaching.com list of benchmarks so I need your help. If anyone knows how to research this marker, let me and the govenment know.

[+RampagerBOH]

After my first day of geocaching, I found this old benchmark near the bay while walking home.

 

 

This wasn't found on the geocaching.com list of benchmarks so I need your help. If anyone knows how to research this marker, let me and the govenment know.

 

BTW, the coordinates are 30 07.0860N, 85.35.3580W; found in Bay County, FL

I hope this helps.

[Bill93]

I couldn't find it in the NGS data base (from which the geocaching list is a snapshot) by searching within 2 miles of your coordinates. This is mildly unusual for a USC&GS disk, but not unheard of.

 

See the pinned thread above for more info.

[Papa-Bear-NYC]

It's a fairly rare type of disk. The circle indicates it a tidal benchmark but the inscription reads "Hydrographic Station". The lack of a line across the circle tells me it's not a benchmark (i.e. a vertical control point), unless the disk was mounted exactly horizontally, and the leveling rod was meant to be placed on the circle.

 

You might find it in the NOS listings for the area. Start with this site: http://tidesandcurrents.noaa.gov/products.html

 

If you know the area (i.e. the name of the Bay or town or other landmark) you may be able to find the right tidal station (each of which consists of a tide guage and a number of tidal benchmarks). Then using the stamping, which looks like "PAT" to me, you might find it.

 

Here's the page for Florida: http://tidesandcurrents.noaa.gov/station_retrieve.shtml?type=Historic%20Tide%20Data&state=Florida&id1=872

 

Perhaps George L (NGS Surveyor) may know what a Hydrographic Station was used for.

Edited January 3, 2011 by Papa-Bear-NYC

[+mtbikedirtygirl]

I have been wanting to get this benchmark for a long time. Didn't think I would find it. But, this might be my lucky year. EF0602 P 2 (Monumented unknow year by CGS). Maybe someone here can give me a guess. This is my favorite BM to date.

 

You can see the spike location. US is located above and BM is located below it.

 

This is another view of the two "X's"

 

The benchmark is located on top of this rock. I noticed a white x painted at the base of it. It hasn't been found since 1982.

 

another view of the benchmark spike

[mloser]

The bolt (it is probably a round headed brass bolt and not a spike) and "USBM" most likely date from the turn of the 20th century, possibly as early as the 1880s by my guess. I searched Google Books and came up with the following: HYPSOMETRY PRECISE LEVELING IN THE UNITED STATES 1900 1903 WITH A READJUSTMENT OF THE LEVEL NET AND RESULTING ELEVATIONS.

 

It appears to be part of a level line that is named x2, with the first letter indicating the position in the line, e.g. A2 through Z2, if all letters are used. This mark is R2 and in Huntsville is Q2 on the city hall. If you scroll up and down in the book you can see the other x2 marks in the line.

 

A quick check the NGS site showed that quite a few of them (I found L2, M2, N2, O2 and P2) are in the database but weren't found at some point. S2 also appears to be in the NGS database but is listed incorrectly as a disk and is actually a carved square.

 

If you want to do some more research you can search the CGS's Annual Reports.

 

I doubt those X's are anything at all. They look to be folds in the rock rather than chiseled marks. First, they aren't mentioned in the 1903 description, second, they don't point to the mark, and third, bench marks (elevation marks) don't usually have reference marks.

 

Edited to fix broken link

Edited January 4, 2011 by mloser

[+mtbikedirtygirl]

Thank you so much moloser for all the informaion on this marker. It will keep me busy for a little while. I do believe that this is P 2. I found EF0602 D 315/1949 just down the track. They are both located as per the discription on the original data sheet. I have attached another picture I took of the location. You can see the mile marker 335 in this photo. I want to thank you so much for the information. Also, Your right it is a bolt "oops". Still new to bench marking and still learning. But, I sure do love it.

 

 

Happy New Year!

 

 

The bolt (it is probably a round headed brass bolt and not a spike) and "USBM" most likely date from the turn of the 20th century, possibly as early as the 1880s by my guess. I searched Google Books and came up with the following: HYPSOMETRY PRECISE LEVELING IN THE UNITED STATES 1900 1903 WITH A READJUSTMENT OF THE LEVEL NET AND RESULTING ELEVATIONS.

 

It appears to be part of a level line that is named x2, with the first letter indicating the position in the line, e.g. A2 through Z2, if all letters are used. This mark is R2 and in Huntsville is Q2 on the city hall. If you scroll up and down in the book you can see the other x2 marks in the line.

 

A quick check the NGS site showed that quite a few of them (I found L2, M2, N2, O2 and P2) are in the database but weren't found at some point. S2 also appears to be in the NGS database but is listed incorrectly as a disk and is actually a carved square.

 

If you want to do some more research you can search the CGS's Annual Reports.

 

I doubt those X's are anything at all. They look to be folds in the rock rather than chiseled marks. First, they aren't mentioned in the 1903 description, second, they don't point to the mark, and third, bench marks (elevation marks) don't usually have reference marks.

 

Sure is weird that those "X's" are there. But, I fully agree. They must mean nothing. Just happy to find this one.

[mloser]

Sorry! The link to the Google book was broken. Here it is again: HYPSOMETRY PRECISE LEVELING IN THE UNITED STATES 1900 1903 WITH A READJUSTMENT OF THE LEVEL NET AND RESULTING ELEVATIONS. One think I noticed in the CGS note that the mark is 8 feet above the tracks, and it looks like it is more like 4 feet now. I don't think that is typical--although a few people here have remarked that tracks are often raised when they are reballasted I have found the reverse to be true in my area--clearances are so tight that there are marks on the sidewalls of bridges stating not to allow the tracks to be higher than that. Conrail completed a huge clearance project in the 1990s that LOWERED tracks in many places. However, I have no doubt the mark you found is the same, as the milepost is a great reference and it obviously has not changed in the last 100 years (335A to 335 is insignificant). Even when railroads DO change their milepost distances they rarely change the location of the mileposts.

 

Now get out there and look for the other old CGS marks! You might be be the first to find since they were placed.

[kayakbird]

'I do believe that this is P 2.'

 

Congratulations, mbdg.

 

You really did start of the New Year with a very 'Good Day' - a thread that you might consider putting this one on. There is also a 'chisel mark' thread that would fit.

 

Sounds like you live close by. If you check out all the points on this level run you may come up with NONPID marks that you could Waymark. I scrolled up through the report a few pages and noticed that the 1900 run from Harriman, Tenn to Woodville, Ala (starts on page 632) lists quite a few 1899 USGS points that were occupied.

 

Happy Hunting! kayakbird

[+Manville Possum]

After my first day of geocaching, I found this old benchmark near the bay while walking home.

 

 

This wasn't found on the geocaching.com list of benchmarks so I need your help. If anyone knows how to research this marker, let me and the govenment know.

That is a really nice find, I would have been thrilled! I list my finds that are not listed BM's in the US Benchmarks category on the Waymarking site.

[NGS Surveyor]

All, Regarding the "HYDROGRAPHIC STATION" disk, “Papa-Bear” is correct that this is a fairly rare type of USC&GS disk. This one may have been used as a tidal bench mark, but since it contains the stamping “HYDROGRAPHIC STATION” I’m going to assume that it was set to control a hydrographic survey. Horizontal positions were determined for these disks using less than third-order (less accurate) methods, see quote below. In most cases, only second-order or better surveys were entered into the NGS database. Hence the survey data for this mark may or may not exist…somewhere… and only on a piece of paper.

 

The following quote is from the HYDROGRAPHIC MANUAL, USC&GS, 1931, on-line at: http://www.thsoa.org/pdf/hm1931/hm1931.pdf . (Note, four versions of the “Hydro. Manual” are available at this site along with other historical and current references on hydrography.)

 

“Hydrographic stations—It is sometimes desirable to locate certain control stations by sextant angles or cuts. When such a station is located by a hydrographic party, it is called a hydrographic station. It may be located by a sextant position obtained at the station (see p. 79) or by cuts from other points. To obtain a sextant cut, the observer determines his position by sextant position and then measures the angle between a previously located station (preferably one of the stations used for the fix) and the new station.

 

When such stations are mountain peaks or similar features, it is a good idea to observe a vertical angle from one or more positions, so that the approximate height of the feature may be computed for possible use by the topographer or in chart construction.”

 

See also my paper on USC&GS, National Ocean Service, and National Geodetic Survey marks at: http://www.ngs.noaa.gov/web/about_ngs/history/indexhUSCGS.shtml , and scroll down to: Bottles, Pots, and Pans: Marking the Surveys of the U.S. Coast & Geodetic Survey and NOAA .

 

There was also a “TOPOGRAPHIC STATION” disk which is also discussed in my paper. This type of disk was positioned by theodolite or plane table methods.

 

GeorgeL

NGS

[NGS Surveyor]

Regarding old USC&GS leveling publications, many of them are on the NGS web site at: http://www.ngs.noaa.gov/web/about_ngs/history/NGSvertical.shtml

 

GeorgeL

NGS