In the trade we call them "evergreens" -- pieces that are, in the flow of daily events, timeless. Well, not quite, for in the hard deadline demands of the news business nothing lasts long. Evergreens at least will keep a few hours.

This particular evergreen should not have been allowed to keep at all, for which I am to blame. But I will submit that for once we really do have a timeless tale to tell.

It is a story of a friendship that survives the passage of generations, the differences of cultures, the drumbeat of history, the savagery of war. In the end, it demonstrates anew an old human trait: that friendships can be forged out of the most extraordinary circumstances, and once formed they possess a strength that surpasses superficial differences in nationalities, races, even language.

Early this spring a letter arrived in Washington from Hong Kong bearing, in small neat block letters, this handwritten address: To: Editor of Washington Mail Washington, U.S.A.

Because of the misleading address, and that fact that it was from overseas, the letter was sent on to the U.S. Postal Service's International Postal Affairs Office on the third floor of L'Enfant Plaza in Southwest Washington.

The letter was opened. It contained a single sheet of onion skin paper filled with Chinese characters, penned in ink. The letter was sent out to be translated. When it came back, a postal employe read: Editors of the Washington Post Washington, D.C. United States of America

Dear Editors :

I request your assistance to publish this letter in your newspaper and help me to locate my American friend, Mr. Slocum . [Spelling based on Chinese phonetic translation].

Mr. Slocum was a major with the "Flying Tiger" wing which was captained by General Chennault. When Mr. Slocum was bombing a Japanese military emplacement in Shanghai at noontime of April 1945, his fighterplane was shot down by the Japanese. My friend and I saved his life when he parachuted to land. We helped him out from the Japanese search and protected him to get back to his base .

He was around 23 years old at that time. He was born in California, and his father was the owner of a sugar refinery. If my memory is correct, his serial number was 427775 or 477775 .

If Mr. Slocum or his friends read this publication, please write a letter to me at 2, Yi Chia Ja, Kao Chia Bing, Ling Chiao People's Commune, Chuan Sha, Shanghai, People's Republic of China .

May God bless you .

Sincerely yours ,

Huang, Ming-Chu

The letter was turned over to Richard J. Greenfield, a postal service international relations officer. He immediately went to work.

Greenfield remembered that Anna Chennault, Gen. Chennault's widow, had been living in Washington, D.C. He checked and found she still was, in the Watergate. With the help of her personal assistant, Jean Mesle, a roster of living members of the old "Flying Tigers" air group that Chennault commanded in China turned up the identical serial number of that first set of figures in the letter.

The name of the man who bore that number was, indeed, Slocumb -- with a "b". But instead of California he lived in a small town in southern Georgia. By a curious coincidence two members of the "Flying Tigers" were listed as living in that same town of Doerun, southeast of Plains and between Moultrie and Albany, Ga.

Greenfield called the postmaster of Doerun. Did he know if a Clyde Slocumb lived in Doerun? Why, yes, he had been by the post office just that morning. Had he by chance been a member of the "Flying Tigers" in the war? Yes, he certainly was. The postmaster supplied Slocumb's phone number; in minutes, Greenfield was reading him the translation of Mr. Huang's letter. Later, he gave this reporter a copy of the translation, and the original letter.

Slocumb remembers how "unbelievably close" to the Japanese he was as he parachuted to the ground across the Huangpu River after his P51 was shot down while strafing the north field of the Shanghai airdrome that day 36 years ago.

"Two Chinese came running up just as I hit the ground. One had a hoe in his hands. I didn't know whether he was going to hit me or help me. He helped me dig a hole to bury the parachute, then he helped me run as fast I could. I had been hit in the left knee by shrapnel, and it was bleeding heavily. I continued to run as fast as I could and when I couldn't go any more, they got me a bicycle to ride. After riding as long as I could, I couldn't do that any more and they put me in a wheelbarrow and rolled me around from place to place."

That began a 43-day odyssey in which Slocumb was moved 100 miles, often under the noses of Japanese troops, by night and day, by land and water in a Chinese junk down the Yangtze, until he reached his American base. A Chinese nurse who tended his wounds later was tortured. Every inch of the way he was accompanied by his new Chinese friends. "I felt so close to the people who did so much for me when I was absolutely helpless," he says. "It's something that draws people together forever."

After the war, Slocumb stayed on in the Air Force, retiring after 30 years' service as a colonel.Now 61, he lives quietly in his home town of Doerun. (He never was from California; that, and the part about his father owning a sugar refinery, are about the only inaccurate recollections in the letter from China.)

As soon as he got the letter, Slocumb wrote a reply, in English, that said in part:

After 36 years I remember so vividly the wonderful Chinese people who made it possible for me to escape the Japanese. The situation looked impossible. Only through the courageous efforts of you and your friends could such an escape be accomplished. I want you to know that I will be eternally grateful for everything you did for me. . . .Thank you for writing to me, for this gives me an opportunity to tell you and the others how grateful I am for what you did. May God bless you always, Clyde Slocumb ."

A letter arrived in Doerun from Slocumb's old Chinese friend. Like the first one, it was in Chinese. Slocumb, who neither reads nor speaks the language, took it to the owner of a Chinese restaurant in his area. The translation was not satisfactory, but the meaning of the fragments are clear: "It makes me so happy . . . waited 36 years . . . so nice to hear . . . ."

He's going out of town soon so he can have it fully translated, and then carry on the correspondence.