When Phillips returned to London at the war’s end, he resumed his studies at the LSE. He took up sociology, a degree that contained some basic economics modules, and became intrigued by the engineering-style mathematical equations that were becoming popular in the new subject of macroeconomics. He started skipping his sociology lectures and disappearing to his landlady’s garage in the suburb of Croydon, where he put together a hydraulic representation of the equations his lecturers had been scribbling on the blackboards.
One of those lecturers was James Meade. Meade might easily have been taken aback when a student who had all but abandoned sociology approached him with a proposal to rework the calculus of economics as a study in plumbing. Instead, thanks to his patronage, Phillips was given the opportunity to demonstrate his mind-boggling machine in the exacting forum of the Robbins seminar in late 1949. It was his big chance, a last opportunity to demonstrate that he had something serious to contribute to the brave new world of macroeconomics.
Cigarette never far from his lips, Phillips began by fiddling around at the back of the array of Perspex pipes and tanks and starting up a pump that had been scavenged from a Lancaster bomber. The pink-dyed water began to squirt into a tank at the top of the machine, and from there flow down from one container to another. The sound of the pump screeched in the background like a kitchen blender as Phillips demonstrated what the machine could do.
The professors were astounded. Perhaps they would have been less so had they known more about his unorthodox education — the differential equations he’d studied by correspondence course, the hydraulic engineering he’d learnt as an apprentice, the mechanical scavenging and repurposing he’d begun on the farm and perfected in the defence of Singapore. The machine worked perfectly. Within five minutes, the entire room was buzzing with excitement at what Phillips had created: the first-ever computer model of a country’s economy.
The Moniac, or Monetary National Income Analogue Computer, is these days often just called The Phillips Machine. It churned out solutions to equations, using hydraulics instead of differential calculus to calculate the answers. It was a simple computer, although not quite as simple as one might assume. It could solve nine differential equations simultaneously and within a few minutes — a feat that was impossible by hand. Even in the 1950s, economic models were worked out by rooms full of human “computers”, typically women armed with paper and calculators to provide the mathematical equivalent of a typing pool. It would be years before digital computers could support economic models as complex as the Moniac’s.
Phillips made 14 machines in all, most Mark II Moniacs, expanded versions of the original machine. The original machine went to the University of Leeds. Others ended up at Cambridge, Harvard, Melbourne, Manchester and Istanbul. Some went to corporations or ambitious governments in developing countries, from the Ford Motor Company to the Central Bank of Guatemala.
