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Local Logging Maps
Though only in fits and starts so far, I’ve been slowly working my way through the maps in my local archives’ collection. We have what you might expect: a mixed bag of local topo and cadastral maps, both current and antique, and some maps donated by locals that themselves aren’t local — old road maps, for example.
But one thing we do have in great quantity: a whole whack of maps that appear to have emanated from the E. B. Eddy Company’s logging operations in my county. I took a few photos on Saturday to give you a sense of what they look like: 1, 2, 3. Most of the ones I’ve gone through so far date from the 1960s, and they’re printed in blue ink (that smears, let me tell you), with coloured highlights indicating areas of interest, on fairly cheap paper — these were maps printed for work, not for posterity.
I’m going to have a hell of a time trying to organize these things into some kind of serial order. Unfolding and flattening them for better storage is going to be fun, too. If you know anything about this kind of map, I’d love to hear from you.
Previously: Question: Cataloguing a Map Collection?
Categories: Energy & Resources
Is the green tint hand-shaded (e.g., by colored pencil)? Other than the green shading, the look and description suggest diazo-process bluelines. If so, the images were created from an original vellum or mylar, and the image was exposed on chemical-treated paper (linen was used for important records) and developed with ammonia.
Don Aday | 02/19/2007 at 5:03 PM | #
At least some of the shading is by hand; I’ve only gone through a fraction of the maps, so I can’t say if that’s the rule.
Jonathan Crowe | 02/19/2007 at 8:22 PM | #
Yes, diazo process - it brings back the smell of ammonia in the morning just saying it.
This was *the* technology back in the day for making large format monochrome copies. We would create a mono-chrome plot on mylar (with either an inkjet or a temperature-based wide format printer). Placing the mylar ontop of special paper, it was fed into the blue-line machine, exposed to ultraviolet light (the black lines acting as a mask) and the pair of sheets worked their way out. Then the blueline paper was fed back into a second slot in the machine where it was dipped through a chemical fixer that darkened the lines and sort of fixed the color.
The speed of the drive wheels controlled how dark the lines would be. There would often be slight slipping of the media as well, so RMSEs weren’t always the greatest if you tried digitizing off of one of those!
You had to be a little careful with the output - being UV derived, they faded in the sunlight or under flourescent lighting, they would also smear and cause my skin to itch. But they were cheap and easy to make, and, compared to the other options available at the time, ideal for the field.
These were still being used by some timber companies on the small end of the Fortune 500 as recently as 5 years ago, believe it or not. Most other users stopped in the late 80’s for fear of all that ammonia exposure.
android | 02/20/2007 at 12:32 PM | #