JOHN A. BURNS, FAIA, is a deputy chief and principal architect of HABS/HAER/HALS. He has lectured and written extensively on topics related to historic buildings, including the technologies of architectural and engineering documentation. HABS/HAER/HALS are part of the National Park Service, U.S. Department of the Interior. The programs document important architecture, engineering structures, industrial sites, and landscapes throughout the U.S. and its territories. The HABS/HAER/HALS collections are archived at the Library of Congress and are also available at http: //memory.loc.gov.