What Is It?

by James Jennings

Mystery object, about 8" (20 cm) long and 9" (23 cm) high.

The above object recently showed up at a middle school in the Seattle area. They were about to throw it out when one of the teachers nabbed it. The only trouble is, we don't know what it is, or even how old it is. Can you help us?

I think we have an answer.
According to Steve Erenberg, this is a "brass demonstration Thermopile in a table stand".
Many thanks!

Disassembled View

It comes apart easily, revealing a complicated ceramic and metal ... something ... at its heart. Note the two thumbscrews posts that are intended to hold something (wires?) securely, with a black ring of insulator where the brass meets the white metal. The front and back faces (about 1" (2.5 cm) in diameter) appear to be a ceramic (badly damaged in the left hand view) with an array of metal contacts. (Heating elements?) The array is 6x5 contacts on one side and 6x4 on the other.

I used an ohm meter to test for electrical continuity. The two posts are not connected. One of the posts is connected to three of the contacts in the grid (upper three in the column nearest to the post) while the other post is connected to the rest of the contacts. Each group of connected contacts is connected to the same group on the other side. I suspect it's busted -- there is a crack through the middle of the thing.

The heart of the beast, front and back.
(click to enlarge)

Except for the heavy black base, it seems to be non-magnetic. Lacquered brass?

Theories

For the pieces:

The thumb screws are for wires, to either power the thing or measure something about it.
The grid is a heating element.
The grid detects sound or light.
The grid has a crack through it.
The cone makes the (whatever it is) directional.
It was made before 1940. (Wild guess.)

For the whole:

It's a focused source of heat or electromagnetic radiation. (But for what?)
It's a microphone.
It's a 3.0 decapixel digital camera. :-)

Feedback

If you have a theory you'd like to share, or if you're a retired science teacher who actually knows what it is, write to me at "djeimz at megaseattle dot com".

I have collected some of the feedback I've gotten so far.

Last modified on September 4, 2010.