Sponsored by the National Academy's National Materials Advisory Board, the conference reviewed the state of research on the preservation of historic stone buildings and monuments. There has been little advancement in the application of scientific knowledge to the problem of stone deterioration since 1932; the reason for this situation is seen as the lack of incentive. The papers cover the following topics related to conservation: salt crystallization in the pore structure of stone, cosmetic problems in Washington, bricks and mortar, coping with water run-off and steel cramps, cleaning and surface repair such as repointing, stone consolidating materials, properties of polymers, and the evaluation of stone preservatives by laboratory tests and natural weathering tests. Summary report of the Committee includes 15 recommendations. -- AATA