I am thinking this note probably refers to USGS using some visual surveying in some areas in order to get the map published and it was not necessarily survey accurate when the features on adjoining maps were more precise. Any other ideas as to the meaning of this note on the 1895 quad sheet?
Probably what we call remote sensing today. Indirect, stealth methods - like triangulation of major features from each end of a measured baseline, perhaps.
Given that some of the field guys may have been trained by Civil War vets, it would have been an acceptable and common method for expedient mapping.
I know a P.E./P.S. that is a member of a Civil War reenactment group that models themselves on the U.S. Army Corps of Topographical Engineers (Wikipedia Corps of Topographical Engineers https://en.wikipedia.org/wiki/Corps_of_Topographical_Engineers&apos ;"> https://en.wikipedia.org/wiki/Corps_of_Topographical_Engineers ). There is a training center (Web site http://www.topogs.org/homepage.htm&apos ;"> http://www.topogs.org/homepage.htm ) for those wanting to understand their equipment and methods.
From what I understand military reconnaissance surveys were a combination of wagon wheel odometers, triangulation (using plane tables at baseline ends) and barometers. I think that after the Civil War some of these men became members of the USGS. The last link above would be a source of much better information than what I have.
Although dated originally 1895, that map is some time after the 1927 projection. I suspect the note refers to a reconnaissance inspection related to a revision date.
Yep, that's still here or nope, that's gone type of thing.
As described in 1886...
I suspect that the quad map is compiled from data of various dates and qualities.
The image you show has 3 dates on it. Without knowing the date that note was put on the map it's hard to guess what the older, rougher methods were.
Maybe they had their scanner loaded into a hot air balloon.o.O
BajaOR, post: 342923, member: 9139 wrote: The image you show has 3 dates on it. Without knowing the date that note was put on the map it's hard to guess what the older, rougher methods were.
The same note is present on the 1895 quadrangle