zdv Posted February 9, 2003 Share Posted February 9, 2003 I've now found two BMs that look like the one below. One was shown on a USGS topo map but the other was not. The tablet design is different from most I've seen, so I'm guessing there is some kind of significance there. However, neither marker shows up in the NGS database. Any ideas what it is? http://rm-f.net/~zdv/photos/20010824/blackmanbenchmark.jpg Quote Link to comment
+GEO*Trailblazer 1 Posted February 9, 2003 Share Posted February 9, 2003 I have found several,with a cross cut in the Stone,It is probably one of the Original Stones of the Public Lands Survey prior to the adoption of the Standard Tablet.The one that you have a picture of.I don't know for sure without a detailed inquiry into the marks,this can be done through your County Court House Records books. WHEN ALL ELSE FAILS *GEOTRYAGAIN* http://www.msnusers.com/MissouriTrails Quote Link to comment
+Kewaneh & Shark Posted February 10, 2003 Share Posted February 10, 2003 The tablet design you are wondering about seems to me to be a design that was used around the turn of the century. I've found a few like that and they were all in the early 1900's. Sometime in the first quarter of the century the design changed to the more simple designed brass caps that are seen more often. Survey Tech could probably give more specifics on dates and purpose of the design changes. I found one very similar to yours yesterday set in the wall of an old courthouse. See GU1072 and GU3368. The crosses are in the benchmarks to give the surveyors an exact location to measure to. Think of them like cross hairs in a telescope. On some marks the crosses are smaller, or the vertical line may be nearly non-existant. Sometimes it's not a cross at all but only a dot or punched hole in the brass. However the cap is marked, it all serves the same purpose: just to let someone know where the exact point is. Keep on Caching! - Kewaneh Quote Link to comment
survey tech Posted February 10, 2003 Share Posted February 10, 2003 Thats right, its just an early design. Many designs were tried and some used for many years, so I could not say exactly how old it is. Quote Link to comment
zdv Posted February 10, 2003 Author Share Posted February 10, 2003 Thanks for the info. Neither one is in the database, which must just be a coincidence. Here I was thinking I had found something special! Quote Link to comment
+Kewaneh & Shark Posted February 10, 2003 Share Posted February 10, 2003 You found a piece of history. That's pretty special. Keep on Caching! - Kewaneh Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.