Expert: Bob Berry - 10/10/2011

Question
I bought some insulators and don't know the value,i have looked and have found some similar but none that match the description. please let me know the name and value of this insulator.

Answer
Hi Rachel,

Your insulator is a fog-bowl style.  This unusual style was made from two pieces of porcelain that were glazed together.  The idea was to have a closed-in area around the pin to lower the affect of contamination or fog that would lower the insulation value.  These were frequently used in high pollution areas or along the coast where moist air was frequent.  I'd date yours from the 1920's into the mid 1930s and it was made by the Locke Insulator Company based out of Victor, NY.  These are quite collectible and trade in the $20-$25 range.   Here is a link to some similar styles:

http://www.nia.org/general/porcelain/uni_7.htm

Check out the bottom of the page.  

         Hope this helps,  Thanks, --Bob