"I was planning to take a cross-country trip to visit my parents," he said, "and I decided to stop at cemeteries along the way."
Science is frequently a matter of trial and error.
Meierding's original hypothesis was that greater weathering would occur in rainy areas than in dry places. On his first cross-country swing, that is indeed what he found. But further study showed that his assumptions were incorrect.
"How I found out I was wrong in my hypothesis was by measuring stones in Hawaii. They have as much as three times the amount of rain as on the mainland, yet the stones were in perfect condition," he said.
Meierding measured a minimum of 30 stones in each cemetery. He developed a scale, based on the legibility of the carving on the stones and differences in their thickness between the top and bottom, to assess their condition.
He was then able to develop a number-based rating for each cemetery that described the overall condition of the tombstonesfrom excellent to seriously deteriorating.
"These are real quick and dirty measurements," he said. "It's the sheer volume of measurements that makes the data useful."
When he mapped his findings, he found that the most serious degradation had occurred in areas where there was heavy coal burning 60 to 70 years ago.
"A lot of the damage that was assumed to be relatively recent actually occurred in the 1930s, when industrial sites were located in the cities," he said. In rural areas, "the map exactly matched the high-sulfur coal fields."
Geography Meets Geology
Looking at things from a geographical perspective can provide a global view of the problem. Meierding's work with the university's art conservation department is a case in point.
"Art conservationists may look at a building or a sculpture and see that it is sustaining damage, but because they're looking at just one small sample, they have no way of identifying the source of the destruction," Meierding explained. "That makes it difficult to know what preservation techniques might be most effective."
Not all air pollution is the same. Brownstone buildings in New York City and Philadelphia are deteriorating as a result of their exposure to air pollution from the burning of high-sulfur coal. In Los Angeles, on the other hand, buildings exposed to high levels of smog don't suffer a similar fate because the air pollution is primarily made up of nitrous dioxide, rather than sulfur dioxide.
Tombstone-based research also can be useful in pinpointing some issues of environmental concern that merit in-depth study.
"In the 1980s, the government gave out a lot of moneyin the hundreds of millions, I thinkto study the effects of acid rain," Meierding said. "If they had been able to map some of the effects of air pollution first, they would have been much better able to target the research dollars."
Fortunately, the deterioration of historic buildings, monuments, and cemetery stones has slowed dramatically since World War II, in part because of clean air legislation, he said.
"Mapping also tells you what you can ignore," he said.
When he was studying cemeteries in mountain ghost towns, he visited a cemetery in Leadville, Colorado, where the old gravestones were in very bad shape. "I thought it was the effects of frost, until I mapped the findings," he said. There were many other towns at the same elevation with no damage, so frost could be eliminated as the cause.
"It turned out," Meierding said, "that at one point in time, Leadville had been the smelter capital of the West, processing gold, silver, and other ores mined during the Gold Rush era." Pollution from the smelting process had accelerated deterioration of the tombstones.
The importance of research such this, said Meierding, is simple: "You can't deal with the effects of pollution if you don't know the cause."
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