warren barbour began to think the tiny faces would yield an answer. arbour: during my dissertation research, i occasionally would run across figurines that had fingerprints, and they sort of added a humanity to my work, and i started looking for them and they sort of brought me closer to the manufacturer of the print. i started wondering who he was and i figured i would never be able to find that. and i started wondering whether or not i could find something else out about them. keach: barbour's curiosity led him to the modern science of fingerprints where he discovered that with a large enough sample he might be able to discern the gender of the person who made the print. males have wider ridges. females have narrower ones. through trial and error, he devised a technique to make permanent molds of the fingerprints. from these he began to construct a sample. finally, an intriguing discovery -- direct evidence that one set of workers was being replaced by another. barbour: it appears that the early handmade figurines were made by females. after the esta