Somebody with whom I worked about ten years ago once told me that a means of transmitting a photographic image across wire existed as early as the late nineteenth century. The guy had a B.S. in electrical engineering from Georgia Tech, so I assume he knew what he was talking about. He told me a few things about the device, but he couldn’t remember its name or the name of its inventor. He said that it was invented by a Scotsman, and it consisted of three rotating plates with curved cuts in them. When the plates were rotated, they would create a sequence of square holes which would appear right-to-left and top-to-bottom (I’m not explaining that very well; I’m drawing a blank on how to best describe it). A light was passed through the holes, and then through a photographic transparency, and then would fall on a bank of photovoltaic cells. This would generate analog currents that would travel along the wire. At the other end, you essentially had the same machine set up in reverse. The current flowing through the wire would be converted to light of varying intensity, which would be projected onto photographic emulsion. Like I said, I’m really not explaining this very well. But did this device really exist, and what was it called? I just can’t seem to find any information on the subject.
IIRC but I could be wrong, the first fax machine was built by Scotsman Alexander Bain in 1843 to transmit a picture of a new calf. That’s right, the fax machine was invented before the telephone it used telegraph lines.
From Wikipedia, for Fax (History section)
So it sounds like your co-worker had it right. More details would be interesting.
When I Googled Bain I found this:
http://www.hffax.de/html/hauptteil_faxhistory.htm
I’m still sifting through it right now, so I’m not sure which machine pictured is the one I was describing.
I remember watching a TV program which recreated a primitive “fax”… one guy was walking back and forth in “scanning” pattern across a huge sheet of paper with a picture on it, and shining a flashlight while he was walking over dark areas, switching it off when he was on white areas. The other guy some distance away was walking in the same pattern across a blank sheet of paper, and marking it with a paint roller each time he saw the torch shining in the distance.
Googling… ah yes, Local Heroes with Adam Hart-Davis, and it was Bain’s invention he demonstrated.
I’ve seen a 1930’s movie where pictures were “wired” to a newspaper using a machine which resembled your description.
I saw this on “The Day the Universe Changed” too
I saw something similar on an episode of “The Secret Life of Machines”.
Here you go the whole lot of Secret life of machines available free (with permission of Tim Hunkin, the writer/presenter). And the fax machine is there.
Not to hijack, but optical telephony was invented in 1880…
There have been many ideas that were, so to speak, before their time…
Huh. That’s even more interesting than the device that I was asking about.
I built one of these, for a science project when I was 14. The transmitter was a mirror glued to a speaker powered by a small amplifier. The receiver was a silicon photocell and used the Fresnel lens from an Overhead projector to focus (we had neither the skill nor the patience to grind a big parabolic mirror). It really worked pretty well, got to about 500 meters range of a sunny day.
Si
The March, 1905 issue of The Technical World had an overview of competing wireless telephony technologies of the time, including the photophone: Wireless Telephony.