We use large amounts of cement in stabilizing archeological ruins. Where can we obtain hydrophobic cements, such as those described on page 7 of the January 1973 article on Special Cements?

These are commonly made in the United States under a variety of names that usually include the word "waterproof" in the title. They may be obtained from the following sources: Bessemer Cement Company

Subsidiary of Louisville Cement Co.

510 Hanna Bldg., Cleveland, Ohio 11115Coplay Cement Manufacturing Company

Coplay, Pennsylvania 18037

General Portland Inc.

Trinity Division

2800 Republic National Bank Tower

Dallas, Texas 75201

Martin Manetta Corporation

Capitol Cement Company Division

One Hamill Road, Baltimore, Maryland 21210

Medusa Corporation

P.O. Box 5668,

Cleveland, Ohio 44101

Monolith Portland Midwest Company

American National Bank Bldg., Room 410

17th and Stout Street, Denver, Colorado 80202