some type of insulator for a  electrical system?


On Mon, Apr 7, 2014 at 10:11 AM, Evans, Lynn (DNR) <[log in to unmask]>wrote:

> Hello all - We have a mystery glass object, a thick, hollow disk, with the
> center cut out.  It is 4.75" in diameter; the slightly off-center hole is
> 2.25" in diameter; the disk is about 2" deep.  One side is flat, and has a
> rectangular hole through it (1.75" x 1.5").  You can see an image at the
> link below:
>
> www.flickr.com/photos/64404343@N02/13694786095/<
> http://www.flickr.com/photos/64404343@N02/13694786095/>
>
> The object was found in a c.1910 dump on Mackinac Island, Michigan.
>
> Any suggestions?
>
> Lynn Evans
> Mackinac State Historic Parks
>