A persistent area of interest for me is cartography; the science of mapmaking. I have a substantial collection of maps (both printed and digital), including a few that I’ve made. However it’s historical maps which are often of the greatest interest, for those point out features which may be worth photographing (especially churches and railroad structures).
Rutgers University has an online resource for maps at the Rutgers Cartography Lab. One of the maps in the collection is a 1913 Farm Journal map of southern New Jersey.
One quickly notices a proliferation of small red numbers labelling every road. What are these numbers?
To understand that, we have to think about the purpose of this map. It was published by the Farm Journal of Philadelphia, as a finder’s aid to go with their Directories. A directory was published for each county in the Farm Journal’s coverage region (which in 1913 comprised most of Pennsylvania, southern New Jersey, Delaware and Maryland). For Gloucester County New Jersey, the corresponding directory is online in digital form at archive.org.
Once you see the directory, it becomes clear what the numbers are – they’re road numbers, similar to a modern [printed] map’s row-column index. In 1913 few roads outside of a town had names; and if they did, it was to name the endpoints (Williamstown-Glassboro Road) or a prominent feature (Alms House Road). Thus for a directory and map to be of any use, the publisher had to impose some form of organization.
To understand how this works in practice, an example is in order.
From the directory for Deptford Township, I’ve extracted this fragment, and highlighted one entry in yellow, two in light orange. In yellow, Chas Alley is a shoe cutter located near Almonesson on H19 (a road marked on the map). The orange highlights are for H33 near Blackwood.
Looking on the map, road 19 is quite visible as a segment just northeast of Almonesson; and road 33 is the stretch between Fairview and Blackwood.
The roads are numbered starting in the northwest corner of each township and ending in the southeast corner… or from upper-left to lower-right.