About the Authors H. Leslie Simmons is a renowned expert in the materials needs of builders and architects. He is the author of a number of books published by Van Nostrand Reinhold, including Construction, Principles, Materials and Methods, The Architects Remodeling, Renovation, & Restoration Handbook, and a series of books related to repairing and extending building materials and systems. Richard J. Lewis, Sr. is a chemist with extensive experience in air and industrial pollution measurement, industrial hygiene research, and toxicological and chemical information systems. He is the author of numerous chemical references published by VNR, including Sax’s Dangerous Properties of Industrial Materials, Hawley’s Condensed Chemical Dictionary, and Rapid Guide to Hazardous Chemicals in the Workplace.