Do you find the text on old gravestones hard to read, and even harder to photograph? Help is as close as a can of shaving lather. But it can get a little messy, so you may want to take along an assistant.
Simply place some lather on the face of the gravestone and work it into the engravings. After the lather is well into the carvings, wipe off the excess with towels.
The lather is slightly basic in pH and won't harm the stone or its carvings. And the next rain will wash it off. Don't forget to wipe the excess off the assistant before you let him back in the car.