Description from the artist, Mark Totman - 
"I have a photograph taken in 1910 of the OMMs.  The features were sharper then and the segments of cracked granite were very clear which I attempted to capture.

The material I used was single sided printed circuit board. The top layer of copper was outlined with the image, and then each segment was cut out with a scroll saw. Each piece was then cleaned and polished with steel wool and then treated with a variety of materials.  Finally, the piece was coated with a clear spray varnish for protection.

I have made a number of these, including one that hangs in the office of the New Hampshire speaker of the house, Sherman Packard."

Image is about 8” wide