090113-1518 EST
chris:
I have tried to get some additional information. From what I have learned my guess is that it was not electrical, at least not from internal wiring.
The fire was spotted very shortly after it started. Response time of the fire department was very fast. Although the photo after the fire looked bad there was little internal damage. Apparently there will need to be some rebuilding of the porch roof.
This is the one building in the Menlo Park complex that is virtually all original. The rest of the Menlo Park buildings are largely recreations because of their poor shape by the 1920s.
Somewhere in the village I vaguely remember some exposed wiring. This might have been in Edison's lab (almost certainly there), machine shop, or the boarding house.
At some point I will put pictures of some of the Edison buildings and equipment on my web site. But not likely to be soon.
In the early years of Greenfield Village on February 11th telegraph messages were sent from the Smith's Creek station to the Edison family. In 1947 on the 100th anniversary of Edison's birth I was one of two that sent the messages. This was using a hand key connected to Western Union lines. In attendance was R. H. Underwood president of Western Union. Mr. Ford was in poor health and was not present.
In a photograph of me sending a telegram is the Western Union message form, but I can not read the details. For some reason a number of years ago this telegraph table was rotated 90 deg. from its original position.
Also in the Menlo Park lab, on the second floor, is a corner table with a telegraph key. I believe this was connected to Western Union in 1929. Edison had very close ties with Western Union.
In the early 1990s I met and talked with Edward Bernays at a Village event. He is the person that General Electric used for promotion of "The Light's Golden Jubliee" in 1929. See Wikipedia:
http://en.wikipedia.org/wiki/Edward_Bernays
He told me that he was invited to a dinner with Ford and Edison and thought there might be some great discussion on some new idea. It turned out that Henry ask Tom what keeps you in such good health? Edison's reply was that his wife kept him supplied with "Carter's Little Liver Pills". So Bernay said the rest of the evening was on this subject. It should be noted that Ford had a great interest in food, and in the 1930s was backer of soy bean usage for food and products. This included soy beans processed to replace other foods --- like burgers, whipped cream, etc. The Ford Motor Co made paint and plastics for production from soy bean oil for many years.
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