Modeling Reality: Physical Data Visualizations

Jason Forrest
Mar 11 · 7 min read

Ok, so it’s been a week since Duncan Swain kicked off the Historical Viz Digest of the Data Visualization Society, but what an amazing week it’s been! The group is now comprised of 265 members with an incredibly active core posting roughly 10–20 literally mind-blowing items a day.

One of the more amazing threads that popped up this week was a series of posts highlighting various three-dimensional representations of data. It all started with Stephanie Tuerk’s post about an exquisite two-dimensional visualization, Harold Fisk’s 1944 set of maps showing the geological history of the Mississippi River Basin.

Left: Harold Fisk, Geological history of the Mississippi River Basin, 1944 link

Harold Fisk was a cartographer for the Army Corp of Engineers who studied the evolution of the course of the Mississippi. His 1944 report, “Geological Investigation of the Alluvial Valley of the Lower Mississippi River,” contains a series of maps that do not just document the current location of the river but also stacks the historic layers in order to show the flow over time. In the introduction of the report, Fisk describes how he utilized the data from approx. 16,000 borings, over 3,000 of which penetrated its entire depth, to create the chart. It’s a work of scientific artistry — a blend of engineering rigor and sophisticated graphic depiction that conveys the complexity of natural forces.

But it turns out that Fisk wasn’t alone in his study of the Mississippi. Duncan prompted this week’s interest in three-dimensional visualizations when he shared this link from Atlas Obscura outlining the 1943 scale-model replica by the US Army Corps of Engineers. “It is the largest small-scale model ever built, representing 41% of the US in miniature, and the more than 15,000 miles of rivers that make up the Mississippi river basin laid out in eight miles worth of tiny, winding streams on 200 acres of parkland.”

Postcard from the Mississippi River Basin Model, link

ELMalvaney elaborates on the Preservation in Mississippi blog, “The Mississippi River Basin Model is the largest small-scale working model in existence. The reason it is so large is simply because any scale model of the Mississippi River Valley will be large. Moreover, finding a suitable scale to properly model the various hydraulic events in the valley proved to be a challenge during the design stage of its construction. The resulting model covered several acres. A working scale model of the Chesapeake Bay is the only other similar model in the United States.

“Started in 1943 by the U.S. Army Corps of Engineers, the Mississippi River Basin Model was designed to study floods, drought, and other weather events. The early excavation was carried out by German prisoners of war, who were captured in North Africa when Rommel’s Afrika Korps was destroyed by Anglo-American forces. Later concrete work [is] by local Jackson contractors. The model was completed and ready for use in the early 1950s. Interestingly, a day on the river can be simulated in just 5.4 minutes using the model.”

The Corps finally closed the project permanently in 1993, and the City of Jackson abandoned it in 2006. Amazingly, the World of Decay blog has tracked down the exact location and documented the current crumbling state of the model as of January 2010.

Three-dimensional model of electricity consumption in Manchester

Three-dimensional model of electricity consumption in Manchester, 1954–1955, Museum of Science & Industry Manchester link

Duncan also shared another three-dimensional visualization, a 1955 model of the accumulation of electrical consumption by the planners of Manchester’s Central Electricity Generating Board. Showing electricity demand by the hour, day, month and year, this collection of charts forms a 3D visualization of energy data in the UK from the years 1951–54. Acquired by the Museum of Science & Industry, Manchester, the model is significant as a tangible record of past practice, both of the electricity supply industry and its consumers.

Alice Cliff and Jenny Rinkinen explore this amazing item further in their detailed 2018 essay: “It is comprised of 675 cards, each of which is known as a ‘load curve’ or ‘load profile’, referring to demand as ‘load’ on the grid system averaged over a time interval of a given duration, in this instance thirty minutes. Assembled as a 3D chart over a longer time period, it was known within the electricity supply industry as a ‘load model…. this object sits at an intersection both of modeling and of conceptualizing energy. It was one of the last hand-crafted data visualizations and is a manifestation of a process of collating data on record cards that was familiar to many office workers of the time, but that was about to disappear from working practice as computers became more commonplace.”

They continue, “Each load curve is characterized by a period of low night-time demand. The night-time base load most likely consists of activities that were either in constant demand for electricity, such as… street lighting, night-time storage heating, or some commercial activities such as the working of press office machines, newspaper printing, or bakeries. Even though the object does not give us clues about what electricity was used for, some cards are an exception. For example, the death of Queen Mary on 25 March 1953 was marked down on one of the cards as a special event causing a peak at 03:00 due to a sudden press load from newspaper printing.”

A MONIAC at Roosevelt College, pictured with economics professor Abba P. Lerner (Bettmann/CORBIS) link

Finally, inspired by the Army Corps of Engineers’ physical model of hydraulic events in the Mississippi River Basin, Stephanie shared this amazing post about the MONIAC, a physical model of the economy by New Zealand economist Bill Phillips, which itself drew from the mathematics of fluid dynamics. Phillips constructed MONIAC as a machine to demonstrate, and at the same time calculate, the effects of adjusting different inputs into the mathematical model.

In a 2007 Reserve Bank of New Zealand Bulletin New Zealand central bank publication, Tim Ng and Matthew Wright describe the functioning of MONIAC this way: “Separate water tanks represent households, business, government, exporting and importing sectors of the economy. Colored water pumped around the system measures income, spending, and GDP. The system is programmable and capable of solving nine simultaneous equations in response to any change of the parameters, to reach a new equilibrium. A plotter can record changes in the trade balance, GDP and interest rates on paper. Simulation experiments with fiscal policy, monetary policy, and exchange rates can be carried out.”

The Moniac machine in use at a lecture at the LSE with professor James Meade in 1993 © LSE Library link

In a 1995 article for INC. Doron Swade writes “Phillips was familiar with emerging electronic technologies; he knew that electronic computers were up to the task of economic modeling. The problem was not computer processing power but visual display. Phillips wanted to demonstrate economic behavior, to show students immediately and clearly how the elements of a national economy interact. Because the early computers had no visual-display units — no monitors, no screens — the behavior of the mathematical model remained hidden. Phillips’s choice of hydraulics and transparent plastic was deliberate, and his reasoning sound.”

Fourteen machines were created and sent primarily to educational institutions along with versions going to the Ford Motor Co. and the Central Bank of Guatemala. Eventually, computers improved and the MONIAC was relegated to the basement. Luckily what was old is new again, and a refurbished machine is on display at the Science Museum in London. Here’s a live demonstration of a working MONIAC at the Reserve Bank Museum & Education Centre, Wellington, New Zealand:

If you’re interested in learning more about physical visualizations and related artifacts, then please check out Passed along to the list by Nicolas Kruchten, currently has 327 entries, so there are plenty more amazing examples to continue your journey!

Thanks to Stephanie Tuerk, duncan swain, Elijah Meeks, and everyone over at the Data Visualization Society! To sign up please register at:


The Journal of the Data Visualization Society

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Jason Forrest

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Electronic Musician, UX Designer and Contemporary Art enthusiast. Contact:


The Journal of the Data Visualization Society

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