-------- Original Message --------
Subject: Re: Plat maps]
Date: Thu, 27 Nov 2003 17:48:51 GMT
From: Philip Hoehn <[log in to unmask]>


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Hi Margaret Goodbody:
     I believe that the publication date (or correction date) on Sanborn
maps is a fairly accurate representation of what was current at that
time.  It was probably gleaned over a fairly short period of time just
prior to that date.  Did the surveyor catch every change that occurred,
or were all surveyors totally consciencious, and did they make no
mistakes?  Probably not.  The only consistent problems I'm aware of are
street widths which are not always shown at the correct scale (in some
cases I think they were compressed to fit the page).  Cannot speak about
Baist atlases.
     If you have a list of your holdings?  If so, I'd love to include
them in the Union List of Sanborn & Other Fire Insurance Maps

http://www.lib.berkeley.edu/EART/sanbul.html

D.C. hasn't yet been put on the Web.


Phil Hoehn, Map Librarian
San Francisco -- [log in to unmask]
-----------------------------------
Contractor for David Rumsey Collection:
http://www.davidrumsey.com

-- "Johnnie D. Sutherland" <[log in to unmask]> wrote:
-------- Original Message --------
Subject: Plat maps
Date: Mon, 24 Nov 2003 11:27:33 EST
From: <[log in to unmask]>


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I work in a local history collection (District of Columbia) that
contains plat maps (e.g., published by Baist or Sanborn). These maps
were published approximately every 5-10 years for certain sections of
the city, and are one of the collection's most prized and frequently
used resources.

Occasionally, a patron will ask about the publishers' methodology: did
the surveyors collect information during the course of one year--the
year of publication--or were the data collected over a number of years?
For example, does the 1909 map reflect what was on the ground for 1909,
or might it show what was actually there in 1907?

Also, is there any consensus about the accuracy of one group of maps
over another? Are the Sanborn maps considered more accurate on the whole?

Any advice or information about these maps would be most appreciated.


Margaret Goodbody
Collections Librarian
Washingtoniana Division, Rm. 307
MLK Library
901 G Street, NW
Washington, D.C 20001