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Home arrow Archives   The American Surveyor     

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Written by Letters to the Editor   
Saturday, 10 April 2010

A 543Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

Response to "Taking a Peak at the Datum"
This letter is in response to Douglas Critchfield's letter "Taking a Peak at the Datum" in the January 2010 issue. First, I'd like to thank Mr. Critchfield for bringing attention to the issue of the vertical datum in the definition of heights--it is certainly a critical issue, and will continue to be in the spotlight as NGS moves toward completing the GRAV-D project and redefining the vertical datum to replace NAVD 88.

However, I feel it necessary to address some statements made in that letter. First off, I'd like to put into context Curt Smith's comment that " . . . gravity really plays with GPS, especially in mountainous terrain." Perhaps not the most precise wording, but the point was simply that the geoid, being a function of Earth's gravity field, is highly complicated in mountainous regions and this causes significant divergences of ellipsoid heights (from GPS) from orthometric heights in those regions.

Second, the six-foot difference between NAVD 88 and NGVD 29 does not represent an "open question" on datum accuracy. NGVD 29 is significantly worse at representing true orthometric heights than NAVD 88, this is simply a fact. The reasons range from the lack of corrections (including the use of actual surface gravity data) in NGVD 29 leveling, sparseness of the NGVD 29 network, and fixture of NGVD 29 to tide gauges (which are biased from the geoid by various non-zero oceanic phenomenon), causing a warping of the zero reference surface of NGVD 29 from the actual geoid.

Lastly, the statement that the ". . . only practical way to empirically verify the published height would be to run a few level-loops up to the peak and back" is also untrue. To verify the published height of the peak, rather than running levels, one may use GPS at the peak to yield an NAD 83 ellipsoid height and remove the GEOID09 hybrid geoid model to yield an NAVD88 Helmert orthometric height, which should agree with the published height to a level of accuracy commensurate with the quality of GPS data taken and number of benchmarks used to create GEOID09 in the region. However, this is to verify only the "published" height.

If one is interested in the true orthometric height, which is the goal of the GRAV-D project, then ultimately this same process would be used, but the gravimetric geoid (not hybrid) would be used, and the ellipsoid heights used would be in the geometric reference frame that replaces NAD 83. Further details are available in the NGS 10 year plan, available at www.ngs.noaa.gov/ INFO/tenyearfinal.shtml.

Dru Smith
Chief Geodesist NOAA's National Geodetic Survey
Via the Internet

Please Don't Move to Our Neighborhood
Wendy Lathrop wrote a most revealing article--about her values. We had to read her article Going Out with a Sigh [Jan. 2010] to be sure we didn't read it improperly. Lathrop is a land surveyor, and I believe teaches the subject. However, she seems quite oblivious to private property rights. The thrust of her article is that she and some other community members are so attached to someone else's property that they feel it is okay to destroy the owner's property rights because "in each of our communities, no matter where we live, there is at least one building or one space that makes us stop for just a moment, either out of admiration for its beauty or as a moment of reverie for some past moment in our private histories that the place evokes." Please don't move to our neighborhood.

Lathrop and some of her neighbors were so attached to the home that they felt they had the right to keep the lawful owner from tearing it down and made every effort to do so. In our community, if someone feels that way, they are required to convince the current owner to sell it. Remember the bundle of rights, Ms. Lathrop? How do you figure to steal the owner's right to do with his property as he wishes?

Michael Daly
Arrow Engineering Gallup, NM
Via the Internet

Lathrop Replies
While I am glad that you took the time to read my article, I am perplexed that after reading it twice that you did not hear my message or that you could still accuse me of trampling other people's private property rights.

One resolution to the situation in my township would have been for La Ronda's purchaser to accept the offer of a willing buyer to move the entire structure--who would pay the new owner for doing so, thereby saving La Ronda's purchaser demolition costs. This would not have deprived Kestenbaum of any rights and would have put money in his pocket. Or, Option 2, La Ronda's buyer could have shifted his gaze to the equally large and lovely tree-lined vacant lot just next door to build his new dream home, so that Wohl could have bought La Ronda and left it on site--again saving Kestenbaum demolition and clean up costs.

My closing paragraph was meant to stir readers to become more involved in their local governments, protecting our rights and making a difference, and although using historic structures as an example, not entirely meant to be limited to them. It doesn't matter that we (collectively) disagree, as long as we can have a conversation about it and work together to make the best government to protect both of us. There is some innovation involved in this, some compromise, a lot of careful listening, and quite a bit of learning. And that's what makes our country so special, because we have the right to do it.--W.L.


Mourning La Ronda's Fate
I read your recent article "Going Out with a Sigh" [Jan. 2010 ]concerning the demolition of La Ronda designed by Addison Mizner. I also spent and hour or so online reading about it, and it sickens me to think that this was allowed to happen, knowing that it can never be replaced. I also see that various structural elements are being sold, etc. I have had no success in finding any site that shows interior or exterior photos other than a handful that appear on various links. I can't imagine that a thorough documentation was not done prior to the demolition unless the former owner has all rights and intends to publish a historical book on this mansion. Can you provide any further information? It does not sound like the former owner was destitute; could he not have donated it to the local preservation society as mentioned and take a tax write off? His legacy would have meant a lot more to the locals than it probably does right now.

Alan France
Drafting Supervisor
Cerrone Associates Consulting Engineers
Wheeling, WV
Via the Internet

Lathrop Replies
Thank you for reading my article and for taking the time to investigate it further. Prior to La Ronda's demolition, there was a beautiful website that included a few interior photos, but I can't find its link now. The only approach now is probably to search Google for "images" (not "web"), and use the following four keywords: "La Ronda", "Lower Merion", interior, photo. The main hall was quite impressive. There is now also a website that advertises, "Own salvaged artifacts from Mizner's masterpiece mansion!" and some of the images will give you an idea of the "before" condition. Each of the 20 items shown on this architectural salvage site includes five or so additional photo links showing details: www.ogtstore.com/catalogsearch/ result/?q=la+ronda&gclid=CPu6vMJ0p8CFUVn5Qodq3kMzg Yes, the former owner could probably have done more, but it isn't clear that he knew prior to closing that Kestenbaum intended to destroy the building, especially in such short order. Once title to La Ronda changed hands, Kania could only exercise whatever rights he retained under the clauses relating to salvage.--W.L.

$omething Worth $aving
I am writing in response to Wendy Lathrop's article in the January 2010 issue concerning the La Ronda estate in Florida. I agree, as most people would, that the destruction of a beautiful piece of architecture is sad and a great loss to society. I, like most surveyors, have a true appreciation of history and also respect the right of Americans to possess and enjoy private property. Having spent the last 20+ years serving as a municipal engineer I have heard too many complaints from citizens about what other people do with their property. The most common complaint is how a developer is destroying the woods in the neighborhood. It usually goes like this, "I have been looking at those woods for 10 years and that's why I bought my house so I could enjoy the trees." I counter by pointing out how it is not their property and that the developer is doing everything according to the approved regulations. They are rarely satisfied. I then further state that the developer, while trying to produce a nice plan, is mostly in it for the money and if they make him a sufficient offer that he would probably sell them the property. They are rarely satisfied with that as well. They will then go on about the trees and how nice the neighborhood is and how everything will now be destroyed. I usually end the conversation by letting them know that where they live now used to be trees also. My point is that if something is worth saving, be it a historical estate or a patch of woods, then some entity with funding needs to step forward. I do not believe it is good enough to declare something historic or to set up special zoning. It seems to me to be nothing more than a taking to designate a place as historic and bar the owner from enjoying his property as he sees fit. If the public deems the property to be that important then the right of Eminent Domain should be exercised and a proper value placed on the property. If the public is so inclined to make the required expenditure, then the public will is satisfied. If not, then let the fate of private property remain with the owner.

Joseph R. Dietrick, LS, PE
The Markosky Engineering Group, Inc.
Greensburg, PA
Via the Internet

Lathrop Replies
Mr. Dietrick is absolutely right about compliance with regulations means a project generally has to be approved by a local government. However someone with money did step forward and put his money where his mouth was. In the end it was not that Wohl did not have enough dollars, but that Kestenbaum threw new obstacles into the agreement process before he would allow the building to be moved intact rather than destroyed.--W.L. 

A 543Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

 
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