The author presents a discussion of weathering rates of carbonate rocks from the perspective of a geologist. Reduction of the surface of a carbonate rock progresses generally parallel with the stone surface, while sandstone reduction progresses along zones of weakness, and presents problems not addressed in the present article. Weathering rates can be measured by (1) comparing weathered surfaces with resistant surfaces (e.g. quartz or hornblende veins that stand out); (2) macro stereo-photogrammetry; (3) using old metal plugs as a reference surface; (4) comparing depths of inscriptions on tombstones; and (5) comparing tombstone dimensions from top to bottom (the bottom being nearly unweathered). Method 1 is quick and easy, but conditions rarely permit its use; method 2 works well; method 3 likely overinflates measurements because metal plugs can be forced out by freeze-thaw cycles; method 4 is suspect because of subjectivity; method 5 is questionable for several reasons. The author concludes that a combination of methods 1 and 2 is optimal. A discussion by Richard A. Livingston following the article questions several points related to method 5, and points out the value of a data base of 3000 measured Veterans Administration tombstones (which are of uniform dimensions) for epidemiological studies of the effects of acid rain. -- CAL