5 MATERIALS

1. Stabiltex No. 4 polyester multifilament fabric. Manufactured by Swiss Silk Bolting Cloth Manufacturing Company, Ltd., Zurich, Switzerland. Available in the U.S. through TALAS, 213 W. 35th Str.,New York, N.Y. 10001-1996.
2. Electric Wax Pen with five tips, Catalog No. 21-296-1; William Dixon Company, 750 Washington Ave., Carlstadt, N.J. 07072. 1987 price: $139.75.
3. Curved metal straight edge—1/2 round type erasing shield; Solari Manufacturing Company, Los Angeles, Calif., phone number (213) 731-6313; approximate price $3.45.

ACKNOWLEDGEMENTS

Development work done under National Park Service, Harper's Ferry Center, Harper's Ferry, W.Va. Photographs by Mike Wiltshire, National Park Service, Harper's Ferry Center.