NGS Surveyor

I was in Osgood for the Bilby Tower construction. It was a lot of fun (I mostly watched). GeorgeL NGS Retired

foxtrot_xray, You are correct, Dave's desk is a museum of disks! But, I think I left the long bronze mark in the NGS museum area. G

No, I don't recall. The mark is, I believe, presently in the NGS "museum" area, perhaps DaveD can take a look and post its name and date. GeorgeL NGS Retired

Here is a quote on the subject from USC&GS Special Pub. #247, pages 118-119: "The bearing to the nearest of the eight points of the compass is entered by the letter abbreviation (as N, NE, E, SE, etc.). Ordinarily all bearings should be referred to the true meridian, but magnetic bearings may be shown if labeled "(mag.) ." George L NGS, Retired

Glad you all are able to find these. The one in my paper on C&GS survey marks was from Arizona. GeorgeL NGS, Retired

Very interesting. John Cloud (one of the speakers) works in the NOAA Library and has done a little of research of early USC&GS work. During the Civil War, the USC&GS (then called the U.S. Coast Survey) did extensive mapping. GeorgeL NGS

I recently came across a publication of the U.S. Coast Survey (later U.S. Coast & Geodetic Survey), dated 1877 and titled, “”Methods, Discussions, and Results; Field-Work of the Triangulation.” It is on-line at: http://books.google.com/books?id=BVwOAAAAYAAJ&printsec=frontcover&dq=methods+discussions,+and+results+field+work+of+the+triangulation&source=bl&ots=94tOXQyAvo&sig=ZxJtWIk5c4frn5rrRTyWxG6VFvU&hl=en&ei=vbacTci3CqSJ0QG--bHlAg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBgQ6AEwAA#v=onepage&q&f=false . Pages 8 – 14 are of special interest, discussing tripods, signals, underground marks, surface marks, and observations, and include several drawings. This is the earliest specification for USC&GS triangulation that I have found. The mark section includes descriptions for several different types of marks, including one, an iron cone (sometimes with a rim), that I had never heard of before. This section also mentions references and station descriptions. GeorgeL NGS

Just in the last few days, the NGS Director received the card from inside one of these bottles. The bottle had recently been found in Alaska, on the north side of the Aleutian Peninsula. Amazing since it was dropped in the ocean many years ago! (Likely in the 1950s or 1960s.) GeorgeL NGS

I sent an email yesterday AND voted today, hope all this works. Also, how does one get to the on-line photos, I couldn't find a link? GeorgeL NGS

BeanTeam, I apologize - you are absolutely correct - the photos of the MAGNETIC STATION are yours. I got permission from the other person to use theirs but liked yours better and somehow got confused. I just corrected the new, updated version of the survey mark paper (still on my computer), in both the text (next to the photos) and in the list of credits near the end. GeorgeL NGS

BeanTeam, Yours appears to be brass. The disks made of aluminum are gray and have a somewhat rough surface. For some photos, see my paper at: http://www.ngs.noaa.gov/web/about_ngs/history/Survey_Mark_Art.pdf page 35. GeorgeL NGS

Re construction of disks, see Figure 31 in my paper. It shows side views of 5 different disks. The older ones were cast, I believe, in one piece. The newer ones had the stem brazed onto the back of the disk. Link to paper: http://www.ngs.noaa.gov/web/about_ngs/history/indexhUSCGS.shtml and scroll down to "Bottle, Pots...." GeorgeL NGS

LSUFan - Aluminum disks should probably be listed as "Aluminum Marker" but may not. NGS and NOS both used aluminum marks for several years. AZcachemeister - Your USGS disk is very old and interesting, but not of use for my paper which only covers USC&GS, NOS, and NGS marks. I know that USGS used survey disks a few years before USC&GS, but I don't know which year they started. Thanks, GeorgeL NGS

All, Anyone have photos of any National Ocean Survey and/or National Geodetic Survey survey disks made of aluminum from the years prior to 1981 for NOS, 1975 for NGS Bench Mark disks, and 1977 for Reference Mark disks? Thanks, GeorgeL NGS

All, I'm updating "Bottle, Pots, and Pans..." and any help would be appreciated. I hope to finish the first draft of the updated version today, so please send any comments ASAP. Thanks, GeorgeL NGS

Has anyone recovered a U.S. Department of Commerce, Bureau of Public Roads survey disk? Thanks, GeorgeL NGS

All, I am finally in the process of updating my on-line paper on USC&GS and NGS survey marks. I have included all the info. from this link, but if you have any other rare finds or any that are not mentioned in my paper, (or found any errors or omissions in my paper), please comment now! Thanks, GeorgeL NGS

A few suggestions: USGS disks (U.S. Geological Survey) USACE disks (U.S. Army Corps of Engineers) Most of the rod marks set by NGS are stainless steel, not aluminum. Also, about the year 1900, the USC&GS did a north-south arc of triangulation along the 98th meridian, running through Texas. Some of these marks undoubtedly still exist and some were of the earliest type of disk that USC&GS used - a "cup" shaped disk. I have recovered one of these 98th marks that is a nail set in concrete. See USC&GS Special Publications at: http://docs.lib.noaa.gov/rescue/cgs_specpubs/data_rescue_cgs_specpubs.html especially #54, 88, and 189. Special Pub. #77 covers USC&GS leveling in Texas. Good Luck, GeorgeL NGS

Those "tabs" were only on very early disks. My guess is that they were intended to help resist rotation of the disk. For disks set in bedrock, two grooves would have had to be chiseled out to allow the disk to set flush. The wedge in the stem groove was also only used on early disks. This looks like an excellent idea, but I have never set one that way, so I can't comment on how well it worked. GeorgeL NGS

The specification for setting Reference Marks was that they be within 30 meters of the station mark. Since the standard tape was 30 meters long, this allowed the distances to the RMs to be measured within one tape length. GeorgeL NGS

I have sent a note to the eBay seller of this disk and asked them to remove the disk from sale. I explained that we do not want to develop a market for survey disks for fear that people will go out and pry them from the ground and then sell them on eBay. I do this for every survey disk I see on eBay. GeorgeL NGS

There is at least one U.S. Coast & Geodetic Survey bench mark in the Bahamas. I found it a few years ago by accident, and believe it is a tidal BM. GeorgeL NGS

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

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

In the case of U.S. Coasst & Geodetic Survey (USC&GS) and National Geodetic Survey (NGS) marks, it was common practice to include the initials of the Chief of Party in the description. Sometimes the mark setter's initials were also included. GeorgeL NGS