COMMUNISTS THE YELLOW MAN'S BURDEN HONG KONG'S TWO COMMUNIST DAILIES LAST WEEK BREATHLESSLY RECOUNTED THE EXPLOITS OF ONE CHENG HO, A EUNUCH EMPLOYED BY THE THIRD MING EMPEROR, WHOSE FLEET OF JUNKS EXPLORED THE EAST AFRICAN COAST 80 YEARS BEFORE THE PORTUGUESE GOT THERE IN 1498 . BOTH FRONTPAGE STORIES, PURPORTING TO PROVE THAT CHINA AND AFRICA HAD A LONG HISTORY OF " FRIENDLY INTERCOURSE, " CELEBRATED THE DEPARTURE FOR POST-COLONIAL AFRICA OF COMMUNIST CHINA'S PREMIER CHOU ENLAI, WHO IS THE GRANDEST PANJANDRUM FROM PEKING EVER TO VISIT THAT CONTINENT . THE TOUR, LASTING SIX WEEKS OR MORE, WILL TAKE CHOU AND TWO PLANELOADS OF ADVISERS TO AT LEAST NINE " NONALIGNED " AFRICAN COUNTRIES, WITH A SIDE TRIP TO ALBANIA, RED CHINA'S EASTERN EUROPEAN SATELLITE, AND ON THE WAY HOME, A STOPOVER IN PAKISTAN . COMPETING WITH MOSCOW FOR FRIENDS AMONG UNDERDEVELOPED NATIONS, CHOU EVIDENTLY WANTS TO ESTABLISH THE YELLOW MAN'S BURDEN, EVEN IF CHINA CANNOT EXACTLY AFFORD TO PICK IT UP . AMONG AFRO-ASIAN COUNTRIES, PEKING'S PRESTIGE HAS SLUMPED BADLY AS A RESULT OF ITS REFUSAL TO SIGN THE NUCLEAR TEST BAN . IN AFRICA ALONE, 17 OF 33 NATIONS VOTED LAST OCTOBER TO DENY RED CHINA A SEAT IN THE U.N., WHILE ONLY TEN HAD DIPLOMATIC RELATIONS WITH PEKING . DURING THE FLIGHT TO CAIRO ABOARD A CHARTERED KLM DC-7, CHOU STRIPPED DOWN TO LONG UNDERWEAR FOR A SEVENHOUR SLEEP, WOLFED HEARTY PORTIONS OF RUSSIAN CAVIAR BEFORE LANDING . THOUGH EGYPTIAN AUTHORITIES PROVIDED AN ENTHUSIASTIC CROWD TO GREET THE CHINESE PREMIER, THE OFFICIAL WELCOME WAS SOMEWHAT RESTRAINED . PRESIDENT NASSER IN TUNISIA TO ATTEND CEREMONIES MARKING FRANCE'S WITHDRAWAL FROM THE BIZERTE NAVAL BASE WHEN CHOU ARRIVED GOT BACK TO CAIRO IN TIME TO GIVE A LAVISH BANQUET AT ABDIN PALACE . HE PRESENTED RED CHINA'S PREMIER WITH EGYPT'S HIGHEST DECORATION THE COLLAR OF THE NILE . IN RETURN, CHOU ROSE TO PLEDGE AN ASSOCIATION BETWEEN THEIR TWO COUNTRIES AS ENDURING AS " THE EVERFLOWING NILE AND YELLOW RIVERS . " BUT NASSER SCHEDULED AS FEW MEETINGS AS POSSIBLE, INSTEAD LOADED THE VISITOR'S SCHEDULE WITH TRIPS TO NASSER'S PET PROJECTS, NOTABLY THE ASWAN DAM, WHERE 2,000 RUSSIAN TECHNICIANS COULD HARDLY ESCAPE CHOU'S NOTICE . WHAT WITH SOME $1.5 BILLION IN SOVIET AID AND HEAVY DEPENDENCE ON U.S . WHEAT TO FEED EGYPT, NASSER HAS HAD STRAINED RELATIONS WITH PEKING OF LATE . DAYS BEFORE CHOU'S ARRIVAL, HIS PRESS BELATEDLY CHIDED CHINA FOR ITS ATTACK ON INDIA . THE WELCOME MIGHT BE MORE SATISFACTORY IN COUNTRIES THAT HAVE OR NEED CHINESE TECHNICIANS, LOANS AND TRADE AGREEMENTS ALGERIA, GUINEA, GHANA, MALI . ELSEWHERE, CHOU'S RECEPTION PROMISES TO RANGE FROM THE COOL TO THE CURIOUS, ROUGHLY THE WAY IT WAS BACK IN CHENG HO'S DAY .