--- Begin Forwarded Message ---
Date: Fri, 19 Apr 2002 15:48:13 -0400
From: "Mark A. Thomas" <[log in to unmask]>
Subject: RE: 1:25,000/1:50,000 scale maps from DMA <fwd>
Sender: "Mark A. Thomas" <[log in to unmask]>


We have some of these.  You may not want to catalog them this way, but
all the 1:50K sheets have AMS series numbers in the V8XX range and all
the 1:25K sheets have AMS series number in the V9XX range. It seems at
the very least that it makes sense to call the 1:25 and 1:50 sets as two
different bibliographic entities, each covering the country, even if you
don't want to go to the extreme of cataloging each AMS alpha/numeric
series (which would split each scale into many separate series) or each
sheet separately.

All of our 1:25,000 sheets are pretty old, like 1940s and 1950s. Most of
the 1:50,000 are much newer, like 1980s.  The 1:25K are on the same
7-1/2 min. grid as the USGS topos. The quad names are often the same as
the USGS quads but sometimes different.

--Mark
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Mark Thomas / [log in to unmask] / 919-660-5853, fax:919-684-2855
Economics, Geology, Geography Bibliographer
Map and GIS Librarian / Public Documents and Maps Department
025 Perkins Library / Duke University, Durham, NC 27708-0177

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