As best as I can make out from the photo, the inscription on the tombstone reads:
JACOB KOHLER
DIED
APRIL 27, 1870
AGED
82 Y 8 M 10 D
ELISABETH
wife of
JACOB KOHLER
DIED
DEC 17, 1868
AGED
76 Y 2 M 27 D
Further information about headstones in this cemetery, and the original source data for the image above, are available at http://www.rootsweb.com/~ohrichla/Cem-Clay.htm.