When trying to read inscriptions on tombstones, often times age and weather make the task difficult, if not impossible. Some folks use flour, shaving cream and stiff brushes to clean up the stone but this can be damaging.
Aluminum foil to the rescue! Get the cheap, thin foil and wrap it around the stone. If you have to tape to hold in place, tape only foil to foil. Then using a the softest brush you can find, or a soft foam ball, bush it on the foil over the lettering. When you take it off, you will have an inscription that is much easier to read. Have doubts? Check out this tombstone and this one on Find A Grave and see for yourself.