David Patrick McKenzie

Digital Public Historian

Addendum: Making my own information more accessible

1846 and Boschke maps of Washington, merged together

The two maps, together. I suppose another step would involve superimposing one on the other. Perhaps another time.

This afternoon, as I finished up Visual Explanations, and furthermore tonight, when I returned home from giving a talk and saw Megan’s insightful comment about ability to compare maps, I realized I had made a mistake of parallelism in my previous blog post. When I displayed the 1846 and Boschke maps of Washington, I didn’t display them next to each other, and more importantly, I didn’t display them consistently.

The Boschke map was rotated as drawn, because it was taking in the area of the original diamond-shaped, off-angle District of Columbia–thus was not drawn with north facing up. The 1846 map took in just the city of Washington, and was drawn with north facing up.

So to make them more comparable, I went back to our now old friend Photoshop. I didn’t, for now, bother with making them a consistent color or cleaning any damage (since it’s 12:31 a.m.–so if anyone sees me bleary-eyed in class, you know why!). But I did rotate the Boschke map, and crop it so that it was consistent with the 1846 map. Then, I put the two maps into one image, separated by a small white line. So, here is my work–I saved it at 800 pixels wide, so you can get more of a comparison by clicking on the image. Now it’s easier to see how the 1846 map just shows the city’s blocks, giving an illusion of a built-out city, while the Boschke map shows the city as it actually existed in the late 1850s–having grown significantly even since 1846.

Addendum 2: This week I commented on Claire’s and Richard’s posts.

1 Comment

  1. David,

    I like how you incorporated Photoshop in your map comparison. By rotating the Boschke map, you are effectively comparing it with the 1846 iteration. The comparisons now are much easier, as your audience does not have to make mental adjustments in terms of positioning. In short, they can seamlessly compare one map with the other.

    For me, the next step would be working on establishing a consistent color for both maps. Your post references this change, and I understand the reasons for not pursuing it at the time. When you get the opportunity, I think a change would be beneficial, as I feel a consistent color pattern for both maps would be helpful for your audience. My suggestion would be to match the Boschke map to the color of the 1846 version. As it stands now, the Boschke map is dark, and it may be problematic for people with vision problems to effectively see the differences in both maps.

    As usual, excellent work!


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