Map Scam?

Here at BHS, my job is to catalog maps. We have a wonderful collection of Brooklyn maps from the 1700s to the present; however, when I first started looking at the collection, I noticed that some of the maps were very similar to each other. So similar, in fact, that if you were just casually glancing at them, you'd think they were duplicates. In particular, I became interested in a group of maps of Brooklyn published by A. Brown in the 1860s and 1870s; 3 maps, with virtually identical content...what was going on?

Turns out, producing maps in the 1800s was very expensive, and map publishers came up with some crafty ways of lowering their production costs to increase profits.

Here's how it worked: first, a cartographer would create a "map worksheet," which was a manuscript drawing that served as a blueprint for the printed map. Then, the map worksheet was sent to a printer, who produced a printed version of the map through either engraving or lithography. In both of these processes, a "plate" is made from the map worksheet, and in the printing process, the image from the plate is transferred onto paper, which becomes the printed map. So, the same plate can be used over and over again to make hundreds of copies of a map.

Although the process worked well, making new plates was expensive. So, map publishers began recycling plates that had already been used for earlier published maps. The publisher would make slight alterations to the map plate (such as change the border or some of the lettering), print the map, and sell it is if it was brand-new. Crafty, yes. Ethical, well, you be the judge!