WAYS OF MAPPING / READING A NETWORK
Connections are
not distances.
Stretch a railway into a circle. If every neighbor remains the same, what have you preserved—and what can the drawing no longer tell you?
Rand McNally · 1901Source & rights +
Map of the central portion of Chicago: showing railroads, depots and street transportation lines. University of Texas at Arlington Library, via The Portal to Texas History.
Public domain in the United States by expiration of copyright: published in Chicago in 1901. This is Cartologium’s assessment; the repository’s item page leaves copyright status undetermined.
Open archive record ↗Keep the connections. Change the shape.
In the Chicago study, the selected circuit follows Lake Street, Wabash Avenue, Van Buren Street, and the historically named Fifth Avenue. We mark their turns A, B, C, and D. These letters are labels for reading the diagram; they do not identify passenger stations.
A joins B and D. B joins A and C. That arrangement survives when the narrow street-map trace becomes a regularized diagram or a circle. The shapes look different, but the same edges meet at the same ends. This is the aspect of the railway that the schematic preserves: its connections within the selected circuit.
01 / IN THE CITY
02 / IN THE DIAGRAM
Rand McNally · 1901Source & rights +
Map of the central portion of Chicago: showing railroads, depots and street transportation lines. University of Texas at Arlington Library, via The Portal to Texas History.
Public domain in the United States by expiration of copyright: published in Chicago in 1901. This is Cartologium’s assessment; the repository’s item page leaves copyright status undetermined.
Open archive record ↗Try one edge.
Select Lake Street in the schematic. Move the shape slider from Map trace to Connection ring. Watch A and B move. Their relationship to this corridor does not change.
Spacing becomes a design decision.
The geographic plate places the railway among streets, the river, and the lakefront. The schematic removes most of those surroundings. Its designer can widen a narrow space, regularize a turn, or curve a line to make a relationship easier to read. Equal-looking lengths in that drawing need not represent equal lengths on the ground.
Harry Beck’s Underground diagram offers a historical comparison. The London Transport Museum records his design in 1931 and its first issue in 1933, using horizontal, vertical, and 45-degree lines with evenly spaced stations. Those graphic choices reorganized the railway’s appearance. They did not make the physical distances between stations equal.
Our Chicago diagram asks a smaller question. It traces one closed circuit from two archival plates, then lets you change its form. It does not reproduce Beck’s artwork, model a complete transit system, or make a passenger journey planner. The comparison is between representational choices.
Poole Brothers · 1897Source & rights +
All elevated trains in Chicago stop at the Chicago Rock Island and Pacific Railway Station, only one on the Loop. Library of Congress, Geography and Map Division.
Public domain in the United States: published in Chicago in 1897. The Library of Congress record states free to use and reuse, with no contrary rights advisory.
Open archive record ↗A connection is only the beginning of a journey.
In this simplified model, A–B–C and A–D–C each follow two corridor edges. Counting those edges cannot tell us which journey is shorter or faster. An edge here is a street corridor, not a unit of length or time, and a lettered turn is not evidence that a passenger can board or transfer there.
These are paths through the model; the letters do not establish passenger access.
A distance comparison needs measured geometry and an appropriate scale or coordinate system. A travel-time comparison needs additional information about service, direction, stops, waiting, and access. None of those quantities can be recovered simply by measuring the circle on the screen.
The omission is useful when the question is about the circuit’s structure. It becomes a limitation when the question changes. Before using a map to decide what to do, ask what its lines represent, what its spacing measures, and what evidence your decision still needs.
Read the same corridor three ways.
Start with Van Buren Street. In the geographic view, look for its surroundings. In the schematic, follow its neighbors. In the pictorial view, inspect the prominent Rock Island station advertisement. What question does each representation make easier to answer?
Sources and limits.
This is an editorial explanation of an explicitly simplified model. The Chicago trace uses image-plane annotations from a 1901 geographic map and an 1897 pictorial plate. It is not a surveyed rail dataset. The publication dates describe different source objects, not a synchronized record of service.
London Transport Museum. (n.d.). Who designed the diagrammatic Tube map? [Collection research guide, record 106]. https://library.ltmuseum.co.uk/portal/Default/en-GB/RecordView/Index/106
Inspect the source recordRand McNally and Company. (1901). Map of the central portion of Chicago: Showing railroads, depots and street transportation lines [Map]. University of Texas at Arlington Library. https://texashistory.unt.edu/ark:/67531/metapth310619/
Inspect the source recordPoole Brothers, & Chicago, Rock Island and Pacific Railway Company. (1897). All elevated trains in Chicago stop at the Chicago Rock Island and Pacific Railway Station, only one on the Loop [Bird’s-eye map]. Library of Congress. https://www.loc.gov/item/84694897/
Inspect the source record
Beck’s work is discussed through the museum’s record; no London Underground artwork is reproduced here. The Chicago study provides the archival images, individual rights statements, and comparison method.
Original editorial diagrams © Cartologium. Historical maps retain the rights stated by their individual source records. Revised 11 October 2026.