Before the talking motion pictures there were silent films - action but, no sound - ancient history to modern day moviegoers.

Now, the silent stars of that era are brought to life on a new series of 29-cent U.S. stamps. The designs are the work of artist Al Hirschfeld whose sketches have depicted performers of Hollywood and Broadway for more than seven decades.The silent heroes and heroines illustrated on the new stamps are: Theda Bara, Clara Bow, Lon Chaney, Charlie Chaplin, John Gilbert, Buster Keaton, the Keystone Kops, Harold Lloyd, Zasu Pitts and Rudolph Valentino.

The new stamps come in sheetlets of two each of the 10 designs, for a total of 20 stamps. A banner across the top of each sheetlet reads "Stars of the Silent Screen." Hirschfeld also designed the "Comedians" stamps issued by the USPS in 1991.

The Silent Screen stamps will be issued on April 27 in San Francisco as part of the 37th annual San Francisco Film Festival. Requests for first day postmarks will be honored until May 27.

You may purchase the new stamps at your local post office, affix the stamps to your envelopes, and place in a larger envelope addressed to: Customer Affixed Stamps, Silent Screen Stars, Postmaster, San Francisco, CA 94188-9991. Remember, the deadline is May 27.

- In addition to the stamps, the Postal Service is publishing a book featuring photos of and text about the silent screen stars hailed on the adhesives. The 56-page, hardbound volume is titled "Legends of the Silent Screen." It will be available by mail or phone order.

You may phone 816-455-0970, or write to "Philatelic Fulfillment Service Center, USPS, P.O. Box 449997, Kansas City, MO 64144-9997." The cost is $24.95 per book plus a handling fee of 50 cents.

If you would like to obtain a cacheted, embossed raised letter first day cover with all 10 stamps, you may write to the International Stamp Collectors Society, P.O. Box 854, Van Nuys, CA 91408. The cost is $9.95.