Expert: Bob Berry - 9/23/2011

Question
we live in Alaska and during a recent trip to the mountains, we found several glass insulators.  Some are marked Hemingway-45, Made in the USA, 27-42. The others are marked Kerr Made in the USA 35 72. We were wondering if these are a good find!  thank you

Answer
Hi Julie,

Your first insulator was made by Hemingray glass company in Muncie, IN and is a larger telephone style that was extensively used by A.T.& T. and other companies.  Insulator collectors have developed a numbering system for the various styles and this is a CD 155.  These are almost all clear glass and are pretty common with t $1.00 value or so.  Here is a link to more on the CD numbering system:

http://www.nia.org/general/g_natpt1.htm

If I assume your second insulator is the same style?  If so it should say KERR DP1.  Kerr, based out of Millville, NJ -- Kerr bought out the glass business from Armstrong Co. in the early 1960s and Armstrong had bought the plant from Whitall Tatum in 1938.  All three companies made insulators.  Kerr was the last U.S. company to make glass insulators and they stopped in the mid 1970s.  Kerr pieces are a little more scarce with a $2-$4 value.  

         Hope this helps!!  Thanks, -Bob