Not to be confused with the Glooper.

May 24, 2008 10:46 PM

The Phillips Machine, also known as the Moniac, is a early analog computer for economic modeling with an unusual twist: all of the computation is done by water flowing through its pipes. The flows represent taxes, income, and so on, and the chambers represent balances held by various bodies. Floats attached to pens can provide graphical output such things as GDP and interest rates, and valves can be opened and shut to change the state of the system in real time. You can listen to a BBC radio segment on the origin of Phillips machine, or see a demonstration of one of the only extant working models at the University of Cambridge.

For a more in-depth discussion of its workings, this book has a chapter devoted to the subject, with diagrams, equations, and explanations.

posted by Upton O'Good (12 comments total)

Marvellous! You will find this blog post on Bill Phillips germane.

As I commented there, a Discworld Moniac-equivalent plays an important role in Pratchett's Making Money.
posted by i_am_joe's_spleen at 11:11 PM on May 24

From the same guy that brought us the Phillips Curve. Which I'm sure Terry Pratchett could tell you.
posted by teppic at 11:12 PM on May 24

Interesting set of links. I'd never heard of the Phillips machine until I read the article in the Guardian a few weeks ago. It seems there is a big academic conference on Phillips's life and work coming up shortly to mark the 50th anniversary of the Phillips curve, which probably explains the sudden resurgence of interest in him.
posted by verstegan at 11:29 PM on May 24

I loves me some analog computers.
posted by GuyZero at 11:32 PM on May 24

Excellent post!
posted by pombe at 11:57 PM on May 24

There's another one in the vein in the Reserve Bank museum in New Zealand; the guy who designed and built it is sometimes the one giving tours.
posted by rodgerd at 12:25 AM on May 25

Saw this in a documentary about economics a few years ago - fantastic machine.
posted by fearfulsymmetry at 3:16 AM on May 25

I'll bet it made a splash when it debuted.
posted by subgear at 7:08 AM on May 25

Awesome.
Regarding that first link, you gonna give us a login?
posted by king walnut at 8:36 AM on May 25

king walnut, here's another copy, hopefully this time without access restrictions. I'll ask the mods to switch it in.
posted by Upton O'Good at 9:09 AM on May 25

[switched the first link]
posted by jessamyn at 9:14 AM on May 25

I saw Chris Bissel (author of first link) talking about this, along with video. Very interesting stuff, great post.

When touring Bletchley Park recently I realised what it is about these machines that is just so very very cool, and it's the noise. At Bletchley they have working models of the Collossus and the Bombe: the switches and valves of Collossus and the whirring wheels of the Bombe sound so much more... computery somehow. The water swooshing around the Moniac has a similar effect.
posted by handee at 10:18 AM on May 25