Letters to the Editor - Issue 126

Mapping the Coast I enjoyed the article on geographical benchmarks very much, it was very interesting (“Discovering the Cornerstones of Maine’s Mapping History,” by Jane Crosen, July 2013). I used to live in Wilton, Maine, and there was a brass benchmark, which looked just like the ones in the article, embedded in the foundation of my home. My house was at a high spot north of the village, but it surprises me that the benchmark was in the foundation. I don’t remember the date on the benchmark but it was old. Quite a long way from the coast of Maine but I assume they are all related in some way. Was this triangulation system used to map the whole United States? The author responds: Your letter sent me off on a benchmark map-sleuthing quest. Yes, the National Geodetic Survey (NGS) extended the geodetic survey system from coast to coast. In the “Transcontinental Precision” chapter of his book, The Mapmakers, John Noble Wilford quotes NGS’s director as saying in 1976, “We now have 200 [horizontal] triangulation stations throughout the country,” along with 500,000 [vertical] elevation benchmarks. Regarding “your” marker: You can view the symbols used to locate various types of benchmarks in the USGS’s Guide to Topographic Map Symbols, which is posted online as a PDF. I checked the 1924 and 1956 Dixfield 15-minute USGS topographical maps (at www.unh.edu), and noted a few elevation benchmarks, but it was on the 1968 Wilton map (viewable at topoquest.com), that I found a horizontal trig-station symbol located two miles north of Wilton village, just west of McGrath Road. Bingo! I didn’t spot any others matching your description, so my hunch is this must be “your” benchmark (perhaps it was added as part of NGS’s 1961 nationwide resurvey?). Read the NGS data sheet for benchmark #PF1040, and see what you think (type Wilton’s zip code, 04294, into geocaching.com’s benchmark hunter, then click on “View original data sheet”). The benchmark, dated 1965, is referenced to Saddleback Mountain. The data sheet describes PF1040 as a disk set in a 3' boulder near a small house (or perhaps used in its foundation, or that of your former house built after 1965?). Clearly your benchmark has other stories that are not told in the data sheets. -JC The editors pipe up: Benchmarks were part of the system used to map the rest of the country, and similar systems were used in other countries. They are typically placed by a government agency or private survey firm, and many governments maintain a register of these marks so that the records are available. As the American continent was explored, Congress expanded the U.S. Coast Survey’s responsibilities to include geodetic surveys in the interior; the name was changed in 1878 to the U.S. Coast and Geodetic Survey. Benchmarks are in place all over the United States. Choose a state from the drop-down menu of this web page (http://benchmarks.scaredycatfilms.com/) to see where they are located. —The Editors A Back-Roads Appreciation Thank you for introducing us to the new writer in your stable, Charlotte Crowder. We thoroughly enjoyed “Frost Heave Season” (MBH&H #125). Please let’s have more from this observer of Maine down the back roads. Don’t Change the Almanack Thanks for continuing to publish Rob McCall’s Awanadjo Almanack in your fine magazine. I don’t always completely agree with him (in fact, sometimes I disagree!), but I usually do appreciate where he is coming from. Reminding us to respect the wild world and not abuse our place in it is a message that bears repeating. I also admire Candice Hutchison’s detailed illustrations—together she and Rob create a fine package. It’s the first thing I read each issue, so despite what I said above, don’t change a thing. Honor the History We enjoyed the new back of the book column “Then and Now” by Peter Spectre very much (MBH&H #125). We’ve driven that stretch of Tenants Harbor’s Main Street (I hesitate to write “downtown”!) many a time without giving it a thought—now I look at it with different eyes. It got us to wondering if Peter would be writing any more in his “From Whence We Came” series—I guess it’s obvious that we enjoy the history of Maine and of the nautical world at large—so many greats still to cover! May we put in a plug for Joshua Slocum?