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To: kawhill

7-1/2” topo quad maps were the best ever made.

In the 1980s, the method of calculating latitude and longitude changed when the government went from NAD27 to NAD83 (and then NAD84). In some places, such as Texas, longitude changed by as much as 7 seconds.


28 posted on 08/31/2025 8:39:28 PM PDT by nd76
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To: nd76

I ordered some 7 1/2 quads when back in Boy Scouts.

My town was at the corners of 4 of them.

So it took 4 to cover my local area.

My current town is on the edge of 2. Maybe I need to buy land in the middle of a quad.


30 posted on 08/31/2025 9:06:36 PM PDT by Scrambler Bob (Running Rampant, and not endorsing nonsense; My pronoun is EXIT. And I am generally full of /S)
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