history

The Harmonium

The Harmonium

“First, the machine will produce various sine waves for you on paper after you set values for the amplitude and phase angle. Second, in a reversal of this process, you can trace a curve and use Fourier analysis to extract the phase and amplitude of the curve. All of this is done mechanically.”

The design is an interesting amalgam – open-grain wood and Victorian brass that reminds me of the Difference Engine, mid-20th-century faux-bakelite dials that look like they’ve been salvaged from a WWII-era fire-control computer, and late-20th-century perspex.

The Curta

The Curta

Parts of the Curta, a mechanical four-function pocket calculator capable of manipulating 15-digit numbers, were patented by Curt Herzstark in 1938. He completed the engineering plans while imprisoned in a Nazi concentration camp.

There are 605 components in that little pepper mill, but that doesn’t quite compare with the mechanical computers that stop the glass of the Hale Telescope from slumping:

First light on a large telescope is the beginning of a process of adjustment that may continue for years. Although glass is brittle, it is actually a supercooled liquid. Glass is physically similar to Jell-O. Glass can flop, tremble, and shudder. As a large mirror moves through varying angles, it buckles and droops. The Hale Telescope’s mirror is rubbery. You could push down firmly on it with your thumb and throw the stars out of focus.
[...]
Bruce Rule then tested the glass for signs of slumpage and found that the glass behaved somewhat in the manner of uncured latex rubber – when the opticians leaned the mirror at an angle, the glass would droop and not return to normal shape for quite a while. [He] extracted the mirror-support machines from their pockets in the glass and rebuilt the machines. Rule’s thirty-six mirror-support machines work passively, by means of levers and lead weights. The levers barely move, yet they exert three-dimensional forces throughout the glass, which, in places, reach stresses of up to twelve hundred pounds.
[...]
Each unit, which resembles a piston inserted in the glass, contains an uncounted number of parts. Rule said, “I think that between six hundred and one thousand parts in each unit is a reasonable number.” Since there are thirty-six mirror support units, that would mean that the Hale mirror is held up by as many as thirty-six thousand pieces of metal, most of which move, if only slightly.
[...]
The support units are, in fact, mechanical computers. They react to forces in the mirror and apply corrective action. Rule said “I never recommended that this type of system be tried again.” Virtually everybody at Caltech understands electronic computers, but nobody at Caltech understands mechanical computers, and consequently nobody dares to monkey with Bruce Rule’s support units. Since 1948, there has been one attempt to oil them. The lead weights on the units are adjustable, but nobody wants to adjust them. [The] feeling around Caltech is that anybody who tries to open Rule’s units to see what is inside will get himself fired.
[...]
Once in a while these days, the stars on the video screen turn into hollow triangles – the support units have become stuck. The astronomer turns to Juan Carrasco and says, “The mirror needs exercise.” Juan then slews the telescope from horizon to horizon, from north to south, from east to west, until the stars turn back into points. The nightmare of the engineers is that one night the stars will turn into triangles, Juan will exercise the mirror, and the triangles will get bigger.

- First Light by Richard Preston

Of course, if the Curta is either too modern for you, or perhaps not modern enough, you could always try to track down one of these hybrid oddities.

Glass Seismograph

Seismic Glass

A working glass seismograph: “This is a functional glass seismograph for measuring earthquakes. It stands about 40″ tall, and is about 48″ wide installed. It measures vibrations along the x and y axes (side to side), as well as the z axis (up and down), on three helicorders. Ideally, it should be bolted into bedrock for accuracy”

(check out the glass spinning wheel, too)