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68-eldo

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Posts posted by 68-eldo

  1. The grid coords come from the RCWs (Reports of Completed Works), the standard Army Corps pf ENgineers reference for the various harbor defenses. I acquired these on DVD from the Coast Defense Study Group (CDSG).

    OK, that does it. I’m sending in my membership application and dues. I’ve been thinking about joining but have procrastinated.

     

    Thanks for the push. :)

  2. Another thing you might try is using your chart as an overlay on Google Earth. You can take a JPG and overlay it on Google Earth. The trick is to align the overlay.

     

    Most of the time the fire control towers have horizontal benchmarks associated with them as the locations of the towers and gun emplacements were surveyed very precisely in order to make the fire control calculations as precise as possible. Many of those marks have been put into the NGS database. This helps in aligning the overlay. If you put the LatLon of the NGS marks into GE you can then use them to align the JPG.

     

    The problem I see is that the map you have covers a very large area and it might be difficult to precisely align it. Maybe if you only used small sections of the chart, say one fort at a time. But then you have the problem of the accuracy of the chart its self.

     

    As for Google Earth, I do all the things I mention above with the free version. I there are more features you can use with the paid version but I have not found much use for those. The hundreds of dollars version is for people like our local TV station that uses it to show the location of events in the news as well as the weather and traffic reports. Since you are not using GE for that kind of commercial use you won’t need that costly version.

     

    I loves my Google Earth!

     

    What is your source for your location and other info on these forts?

     

    Last Saturday I got a tour of Battery DeMerritt that had 2 8” guns.

  3. If you are only looking for the coordinates you might try this URL

     

    At the bottom of the post is a URL to download a KML file that has the location of forts and batteries for the harbor defenses of Boston. This is a post by Zardoz50. He has posted similar files for forts and batteries all over the world.

     

    You can then view the file in Google Earth. In Google Earth just click on file>open then select the file.

  4. Learning Corel Draw by osmoses I believe there is a way to designate a certain color as transparent. If you make your background a particular shade of blue (or any other color you want) and designate it as transparent any thing that color will not show up when pasted onto another picture and the background shows through.

     

    I have not done it myself but my wife does it all the time; and she likes to chatter about such stuff, hence I am learning Corel Draw by osmoses. :unsure:

  5. Having watched the Quartermaster plotting the location of the ship while on watch on the bridge, I would imagine the actual scaling was done with dividers and not a ruler. One leg of the divider would be placed on the location of the benchmark and the other leg would be placed on the nearest lat or lon line on the chart (depending on which one you are scaling). Then the dividers would be moved to the side of the chart where the tic marks are and the coordinate read. Then the operation would be repeated for the other coordinate.

     

    How did I do DaveD? :rolleyes:

  6. What I sometimes do is make the map an overlay on Google Earth. A topo map is relatively easy if you mark the location of the adjusted benchmarks first then massage the map until the benchmark on the map lines up with the ones on Google earth.

     

    I did that with a 1938 Topo map and found out about a lot of history in my area. I have been puzzled about a bridge I found in a valley near my house. The bridge is dated 1929. But there were no roads going to it and I could not find it on any road maps. After creating the overlay I could see the bridge was where the plantation railroad branched off and crossed over the main line to climb out of the gulch to the fields on top.

     

    I also made overlays out of old army aircraft landing maps. It’s amazing how many roads are on what were plantation railroads.

  7. Every time I've read a story in the paper about an event I had personal knowledge of, it seems there's been at least one error in fact.

     

    Same here. I refer to it as the obligatory error.

    Actually, it's sort of a journalistic secret handshake. Reporters make mistakes to distinguish ourselves from everyone else. For example, in a story I recently did on Parkinson's Disease I mentioned Mohammed Ali's Nobel Prize in Boxing, an error that no one seemed to notice. (Of course, it was actually the Pritzker.) And I once was forced to buy a round of drinks at a popular press hangout in Belgrade when my colleagues discovered I had failed to make a single mistake in a story I filed. My bad.

     

    Imperfectly,

    -ArtMan-

     

    I’ve heard of map makers doing that. I did not know journalist did that too.

     

    One of those errors had me in hot water for a while. I was a member of a community planning group as a representative of a non profit. The newspaper falsely reported that the non profit was going to build a large building in the town.

     

    I was in deep trouble for committing the group to such a big expense. The were mollified only after I handed over the minutes of all the meetings to prove there was no plan to build that building.

  8. I really can not believe the poor quality of news reports in this day and age. A month or so ago the local news anchor was reporting on the recent eclipse of the sun and said the eclipse was caused by the shadow of the moon crossing the sun. :D

     

    The other anchor then said “This is the last eclipse of the twentieth century”. :(

  9. There must be a way to adapt one of those relatively inexpensive laser levelers that are sold in hardware stores for quick alinement of picture frames and the like for under $100. I see a few in the $20 range and several in the $30-$35 range. These things are not always super precise and the visible range and pattern of the laser might be considerations.

     

    Set it up on some kind of stake, level it. Read the line on a vertical rule on each end and subtract the foreward point from the back point readings to get the change in elevation.

     

    - jlw

     

    A few years ago I got a Bushnell level for Christmas. This device comes with two lenses that create a line or cross in addition to a straight beam. I set it up in my yard and checked it with a water level. My water level consisted of a 50 foot garden hose with clear sections on the ends. With the sprit level in the top set to as level as I could; I set the near end of the water level as close to the height of the laser beam as I could by eye. The beam was pointed at the far end of water level about 40 feet away. I found there was about two inches of vertical play in the alignment of the beam with no noticeable change in the sprit level. In other words the spirit level was not really sensitive enough. It needs a flatter curve in the glass.

     

    Before the Bushnell I was playing with a really cheap level I bought at Radio Shack for less than $10. It was a standard level with a laser pointer in one end. I figured what do I have to lose fro $10? I put the batteries in it, turned the laser on and ponted it at the wall about 60 feet way. I then sighted down the long edge of the level and the laser spot was about two and a half feet off. Way too far off. So I fiddled with the laser and got it aligned somewhat better. The good laser levels are set up so the laser is a convenient distance above the surface it is sitting on, such as 1 inch. This one was set at some very strange distance. It did not come out to any kind of even distance in inches or metric.

     

    I’ve considered making my own laser level. I would use one made out of wood. I would take off the metal end caps and run it through a table saw to cut a groove a half laser beam width deeper than one inch. I would then drill a hole in one end cap one inch from the bottom and the diameter of the laser beam. On the opposite end I would hollow it out to take the guts of a laser pointer. The laser diode would be set in the level to shine along the grove and out the hole in the opposite end cap. With that arrangement the laser beam has to be parallel to the base and side of the level body. Now the question is how sensitive is the spirit level? It must be very sensitive to be used over long distances with any accuracy.

  10. How did that affect traction?

     

    A number of years ago the railroad I work with went out on a section of track that had not been run on for a long time. The grass had grown up over the rails. On the way back (up grade) we lost traction on the crushed grass. Wouldn’t you know it but the sanders were out of sand. I became the sander, scooping up dirt on the side of the track and sprinkling it on the rails in front of the loco. Fun fun fun.

     

    The state now allows us to get the good weed killer so we can keep the tracks clear.

  11. Andyphoto,

     

    A great report and it looks like you had a good time too.

     

    I have a tip for editing, I do all my writing and editing in MSword, then copy and paste into the reply window. That way I don’t lose a lot of work when the window times out.

     

    That won’t help the 4000 word limit though.

  12. Reading some of the page linked to from foxtrot xray’s link I think of President Kennedy’s speech “Ask Not What Your Country Can Do For You …..” These people are living that.

  13. Yeah, I’m kind of fascinated by this one too. I think this will require investigation by DaveD.

     

    The latitude on J 52 (N 36° 56.683) is the same as the latitude for K 52 and the description seems to put it way out of line with the other marks in the same run. So it looks like the description has been mixed up with another mark.

     

    I think the way to find this one is to have a look at the original notes. Or else find a topo map that shows it.

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