This is a 1910 Museum Photograph of the Sierna Mine in Guanajuato Mexico, produced by The Philadelphia Museums. The 9.125" wide by 7" high silver gelatin print shows a line of men on handmade scaffolds mining silver from the walls by dim candlelight. The photograph has been mounted on dark gray heavy cardboard with rounded corners, measuring 12" wide by 9.75" high. The back of the piece describes silver mining in Mexico. The photograph is in very good condition. The cardboard backing has some small chips at three corners, minor edge wear, and slight warping.