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mjcongleton

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  1. I just got back from a benchmark hunt and I am wondering, most of the benchmarks in my county follow along a single roadway or railroad. I don't understand what purpose these benchmarks really had, or have. Why was highway 38 in Monroe county Ohio and one, of many, railways littered with benchmarks every couple miles or so, and all the other railways and highways ignored? Can somebody explain to my what the purpose of placing all of these benchmarks was to begin with? Most were placed in 1934/1935. Thanks.
  2. Solved my own problem. Sorry I can't delete the post.
  3. All of you have some great resources. Sorry it took so long for me to check back. I guess perseverance is the name of this game. I look forward to finding my first DNF.
  4. Thanks Bill and DR. I looked at the 1940 London map. Might make it a lot easier to find the benchmark location. Also it will be pretty cool to go around the county now and look at where old things used to be. Thanks!
  5. Would a GPSr even help here? I have a Colorado 300 coming Tuesday, but even with WAAS I would have thought measuring would be better. Edit: Just reread what Harry Dolphin stated, yes measureing is better. On a side note, is there any way to look at historical USGS maps online? I need a 1935 map for London, OH so I can locate "the center line of a road leading to the Howard Smith Farm".
  6. So I guess the best I can say is that I MAY have found the mark, but there could also be a disk in a cement slab somewhere in the area as well.
  7. I did KZ1547 today. I think the mark is a metal rod set in a square stone. Others who logged this only mention a stone marker with the same of the county on each side. Picture here. I think the actual mark is the square with the metal rod sticking out, but am I right? Could it be the stone pictured above? Also I know, I need to get a camera and carry it with me. My second day at this: Found 3 (if this one counts) DNF 1 (which I believe does not exist anymore since it was embedded in a building which is not standing anymore) Edit: Just reread the datasheet. Says marker is a DB = Bench mark disk, description says mounted on top of a cement monument. Maybe I didn't find it after all.
  8. Double post again. Sorry.
  9. OK It sounds like I wasn't doing that bad after all. I didn't know that the N,S,W,E directions were "approximate". Since I'm off to Home Depo for a Christmas tree anyway I guess I'll pick up a probe and orange steaks. As for a metal detector? What kind? $50 doesn't sound too expensive, I thought they would be more. I also wonder how much faith I should give to these "Mark Not Found" posts. I mean, I can just see an Ohio Deportment of Transportation worker spending a whole 5 minutes before he gives up and takes a smoke break. OK I'm off to find more. An 'easy' one and a 'hard' one. we shall see. Thanks for the posts.
  10. Went out hunting today. Found 2 (easy) marks, missed 3. I would like to explain how I tried to find one of these marks, explain the problems I encountered, and hopefully get some good advice from the experts here. My only tools are as follows: Simple Boy Scout compass. 200 foot tape measure. Datasheet Here is the benchmark in question: JY1158 *********************************************************************** JY1158 DESIGNATION - K 34 JY1158 PID - JY1158 JY1158 STATE/COUNTY- OH/MADISON JY1158 USGS QUAD - VIENNA (1973) JY1158 JY1158 *CURRENT SURVEY CONTROL JY1158 ___________________________________________________________________ JY1158* NAD 83(1986)- 39 53 24. (N) 083 31 44. (W) SCALED JY1158* NAVD 88 - 345.156 (meters) 1132.40 (feet) ADJUSTED JY1158 ___________________________________________________________________ JY1158 GEOID HEIGHT- -32.86 (meters) GEOID99 JY1158 DYNAMIC HT - 344.968 (meters) 1131.78 (feet) COMP JY1158 MODELED GRAV- 980,071.6 (mgal) NAVD 88 JY1158 JY1158 VERT ORDER - SECOND CLASS 0 JY1158 JY1158.The horizontal coordinates were scaled from a topographic map and have JY1158.an estimated accuracy of +/- 6 seconds. JY1158 JY1158.The orthometric height was determined by differential leveling JY1158.and adjusted by the National Geodetic Survey in June 1991. JY1158 JY1158.The geoid height was determined by GEOID99. JY1158 JY1158.The dynamic height is computed by dividing the NAVD 88 JY1158.geopotential number by the normal gravity value computed on the JY1158.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 JY1158.degrees latitude (g = 980.6199 gals.). JY1158 JY1158.The modeled gravity was interpolated from observed gravity values. JY1158 JY1158; North East Units Estimated Accuracy JY1158;SPC OH S - 210,320. 512,000. MT (+/- 180 meters Scaled) JY1158 JY1158 SUPERSEDED SURVEY CONTROL JY1158 JY1158 NGVD 29 - 345.329 (m) 1132.97 (f) ADJ UNCH 2 0 JY1158 JY1158.Superseded values are not recommended for survey control. JY1158.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums. JY1158.See file dsdata.txt to determine how the superseded data were derived. JY1158 JY1158_MARKER: DB = BENCH MARK DISK JY1158_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT JY1158_STAMPING: K 34 1934 JY1158_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO JY1158+STABILITY: SURFACE MOTION JY1158 JY1158 HISTORY - Date Condition Recov. By JY1158 HISTORY - 1934 MONUMENTED CGS JY1158 HISTORY - 1957 GOOD NGS JY1158 JY1158 STATION DESCRIPTION JY1158 JY1158''DESCRIBED BY NATIONAL GEODETIC SURVEY 1957 JY1158''4.5 MI W FROM LONDON. JY1158''4.5 MILES WEST ALONG THE CLEVELAND, CINCINNATI, CHICAGO AND ST. JY1158''LOUIS RAILWAY FROM THE STATION AT LONDON, MADISON COUNTY, 200 JY1158''YARDS WEST OF A SWITCH TOWER AT MYERS, OPPOSITE MILEPOST CLE JY1158''168, AT A GRAVEL-ROAD CROSSING, 50 FEET EAST OF THE CENTERLINE OF JY1158''THE ROAD, 32.6 FEET SOUTH OF THE SOUTH RAIL, 1.5 FEET NORTH OF THE JY1158''WIRE FENCE, AND ABOUT 3 FEET LOWER THAN THE TRACK. A STANDARD DISK JY1158''STAMPED K 34 1934 AND SET IN THE TOP OF A CONCRETE POST. I figured this post would be sticking above the ground, but I never found it. Here is how I approached the mark: 1. Drove to site. 2. Measured 50 feet from road East and placed some rocks on a railroad tie to mark that position. As stated below this is where I started having problems. I actually measured 50 feed from center line and down the railroad tracks which did not run exactly W/E. -Here is where I had my first problem. Neither the railroad, nor the road run exactly N/S or W/E. I used my old boy scout compass as best I could, but found it really hard to site exactly east. Also I did not have my local declination which is apparently 6 degrees 22 minutes W changing at 3 minutes a year. Any good pointers on what tools/how to site East better. I'm supposed to site to true north right? 3. Now I measured 32.6 feel south of the south rail. Again I had the same problems as before figuring out what was exactly south. After this I felt I was "close", but I didn't see a mark yet. Interesting to note here: the line the old fence used to run appeared to be about 10 feet away from the point I was at instead of 1.5 feet away, so I figure I must have been within a 15 foot radius of where the mark should be. - I think a 15 foot radius of where the mark should be is pretty bad. Any pointers on how to get much closer? 4. I started kicking down brush trying to fin the mark. Also when I measured I was measuring from the railroad south I was measuring downhill, but a true 32.6 feet across a horizontal plane would actually put me further than my tape said, so i should have accounted for that right? How do I do that, basic trigonometry I guess? If I can get the angle that is. Also and additional question: The sheet said the mark was about 3 feet below the tracks, so I expected it to be above ground. Is there a good way to figure out where in the air "3 feet below the tracks" is? After my failed attempt I went to the government web site for a updated sheet and noticed a "mark not found" entry was made in 2006. Also there was a larger electrical/cable box in the area, and the local land owner told me that the railroad clears the area of any growth about every 4 to 5 years, so it is possible the cable company or railroad destroyed the mark at some point. Fire away with comments. You won't hurt my feelings. And thanks in advance for helping me to get on the right track here.
  11. I did research recently to determine which GPSr I was going to buy and I don't really agree the Oregon and Dakota are better units. I picked the Colorado 300 (which will arrive next Tuesday) because it had better reception and a quad helix antenna like the 60CSX. The reception of the Colorado is what made the decision for me (that and a $225 after tax and shipping price tag). I would never own an Oregon because I spend 85% of my time under tree cover, so what is the point of getting a GPSr which might/will lose it's lock? Just my 2 cents.
  12. I did research recently to determine which GPSr I was going to buy and I don't really agree the Oregon and Dakota are better units. I picked the Colorado 300 (which will arrive next Tuesday) because it had better reception and a quad helix antenna like the 60CSX. The reception of the Colorado is what made the decision for me (that and a $225 after tax and shipping price tag). I would never own an Oregon because I spend 85% of my time under tree cover, so what is the point of getting a GPSr which might/will lose it's lock? Just my 2 cents.
  13. Does anybody know it I can make a USGS quadrangle one of my custom maps? I have some historic quadrangles that I can convert to jpg, I'm just wondering if a quadrangle may be too big to download into the GPS.
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