tag:blogger.com,1999:blog-21010261.post2726180748146517508..comments2024-03-28T19:28:10.100-04:00Comments on <b>Rock Piles</b>: Old stone walls record the changing location of magnetic northpwaxhttp://www.blogger.com/profile/16647940752050937588noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-21010261.post-70762330153886771412019-03-18T11:21:45.357-04:002019-03-18T11:21:45.357-04:00There are two serious problems with this account. ...There are two serious problems with this account. First, the author simply assumes (as do many professional archaeologists) that Native Americans never built stone walls, either before or after European contact, a proposition that can now be considered disconfirmed. Thus, as Tim points out, a wall which appears on a 300-year old map may be much older than that.<br /><br />Second, there is a Curtiss Hoffmannoreply@blogger.comtag:blogger.com,1999:blog-21010261.post-70378239063933838112019-03-16T09:37:57.281-04:002019-03-16T09:37:57.281-04:00There's a lot more to a row of stones that how...There's a lot more to a row of stones that how it's been recorded for the last 300 years. "What if it begins with something that resembles a snake's head??"Tim MacSweeneyhttps://www.blogger.com/profile/15517237193572593390noreply@blogger.comtag:blogger.com,1999:blog-21010261.post-10095675603513839202019-03-15T14:59:40.426-04:002019-03-15T14:59:40.426-04:00NOAA has a computer model that can determine magne...NOAA has a computer model that can determine magnetic declination in 10 years intervals from 1750 to present for any given longitude / latitude. It is extremely useful for laying our old boundaries from deeds an surveys in GIS software. (i.e. changing the magnetic bearings to true north bearings)<br /><br />https://www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml#ushistoricJames Gagehttps://www.blogger.com/profile/10414241904072160955noreply@blogger.comtag:blogger.com,1999:blog-21010261.post-59397157026346464332019-03-15T08:56:20.961-04:002019-03-15T08:56:20.961-04:00I was hoping the author would be exploring the rec...I was hoping the author would be exploring the record within a single stone wall of the rocks being moved and subject to different magnetic directions over the wall's lifetime.pwaxhttps://www.blogger.com/profile/16647940752050937588noreply@blogger.com