At present all publically available ones for Los Angeles are black and white and some are not high enough resolution to read all the information. Some states have downloaded full-color and georeferenced scans, e.g., Charlottesville, Virginia
Since the period of interest is 1880 to 1930 concentrate on this period. Baist maps from 1921 are available so use Sanborn for earlier. Also information for early is more difficult to obtain. Nominally Sanborn are available for 1888 (first edition) and 1894 (three volumes). As other areas were added, new volumes were created with the date of publication identifying. For example, 1900 Volume Four adds new areas. But the first three volumes may never have been republished, just updated. What's confusing is that the volumes were updated by pasting in new information, and that should change the effective date, but hard to tell what the date of any given page is—depends on the person pasting in the information. And the catalogs of Sanborns online, don't seem to make it clear. Find out the effective date of the CSUN collection, i.e., what is the date of the latest paste up.
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But for this project we'll concentrate on the 1894 edition since it's in the middle of the more difficult period to cover.
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Establish a priority since we don't know how many can be scanned.
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First do the key maps, they show the approximate location of each sheet and have a incomplete "key" (legend) showing what various things mean on the individual sheets. Most of the sheets are scanned as two images (the left and right pages).
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Will want to pull the key out as a separate image, particularly since they may get trimmed off when the three key maps are merged. Having all three key maps will show almost all the streets, but none of the building information that is one the individual sheets
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Resolution. Baist maps from Rumsey are 12491 × 8364 or similar. And they are beautiful and clear. Since this is a lot of work, it's worth doing it well. Virginia Sanborns are 3000 x 3000 pixels per sheet as rotated—unrotated might have been 2500 x 2100 (based on one I rotated back to square). Readable but has jaggies. Can imagine that double the resolutions would be cleaner. The problem is that the image will be rotated which increases the jaggies. 5000 pixels on a side would be good. Can downsize later, but can't upsize later.
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Note date of the page. Nice if can see paste ups
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Scans of any of the pages that indicate the update status. Sometimes in the early part of the book
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Some sheets cover non-contiguous areas or they aren't continuous [need a designation for georef to track]
-Sanborn identifies one sheet as the left and right pages
-Possible file naming scheme Los Angeles 1894 (1910) Vol 1, Sheet 22a where the second date in parentheis is the update date—leave out if unknown. Volume Four should be Los Angeles 1900 (1910) Vol 4, Sheet 212a, i.e., using the original publication date as the first date (CSUN lists them this way)
-If scanned left and right, usually use 'a' and 'b' to designate
-Almost all Volume One downtown maps are needed, but in a pinch italicized ones are less important
-Would be great to OCR Street Index
Volume One Key Map
1
2
3
4
5
6 (covers two areas)
7
8
9
10
11
12
13
14
15
16 (covers two areas)
17
18
19
22
23
24
25
26
27
28 So Cal RR station and river
29
30
Volume Two Key Map
56
57
62
63
64
65
66
67
71
72
73
74
75
79
80
81
83
84
85
86
87 (covers two areas-the small one isn't needed)
88
89 (covers two areas-the small one isn't needed)
Volume Three Key Map
116 (933 Court)
------------ Footnotes
fill = nothing of importance there but fills big gap in map