Art Heller wrote: "I don't know why you guys think that its a spark plug wrench--or even a tire iron--looks like a lug nut wrench to me with the shallow wrench head."
I know that Edison used to sell little glass jars with his name in raised letters filled with oil so that the water reservoirs of lead-acid railroad batteries sold by Edison could be covered with a thin layer of oil to retard evaporation. If Edison could be so preoccupied with putting his name on something so mundane as this single use glass jar, would it be a stretch to think that the Edison Company may have produced a custom made wrench to say, properly adjust his dynamo governor or some other piece of equipment he sold? Tim McCormick
