"They suggested the following procedure for creating the feather impressions: 1) the forgers removed rock from around the tail and ‘wing’ (forelimb) regions, 2) they then applied a thin layer of cement, probably made from limestone of the Solnhofen quarries, to the excavated areas, and 3) they impressed feathers on the cement and held them in place by adhesive material (referred to as ‘chewing gum’ blobs). Attempts to remove the blobs from the rock were obvious—the slabs were scraped, brushed, and chipped. However, an oversight remained in the cleaning process: one ‘chewing gum’ blob and fragments of others were left behind."—*Venus E. Clausen, "Recent Debate over Archaeopteryx."

You can find all of the above material in four issues of the *British Journal of Photography (March-June 1985). Also see *W.J. Broad, "Authenticity of Bird Fossil Is Challenged" in New York Times, May 7, 1985, pp. C1, C14; *T. Nield, "Feathers Fly Over Fossil ‘Fraud,’ " in New Scientist 1467:49-50; and *G. Vines, "Strange Case of Archaeopteryx ‘Fraud’ " in New Scientist 1447:3.