AFRICA TOGETHER AT THE " SUMMIT " THE NORMALLY SLEEPY ETHIOPIAN CAPITAL OF ADDIS ABABA WAS ASTIR WITH FEVERISH ACTIVITY LAST WEEK . CROWDS OF RAGGED CITIZENS STOOD GAPING AS WORKMEN RUSHED TO INSTALL HUGE PORTRAITS OF PROMINENT AFRICANS ACROSS FROM HAILE SELASSIE'S PALACE . FINISHING TOUCHES WERE BEING PUT ON A SPANKING NEW HOTEL . MILE AFTER MILE OF 8-FT.-HIGH CORRUGATED IRON FENCE WAS BEING PUT IN PLACE ALONG MAIN STREETS TO HIDE THE CITY'S SHABBY SLUMS . ALL THE EXCITEMENT WAS IN ANTICIPATION OF THIS WEEK'S PAN-AFRICAN " SUMMIT " CONFERENCE OF SOME 30 AFRICAN HEADS OF STATE . NEVER BEFORE HAD SO MANY LEADERS OF AFRICA SAT DOWN IN THE SAME PLACE AT THE SAME TIME, AND THEIR PROUD HOST, THE AGING (70) ETHIOPIAN EMPEROR, WAS OUT AT THE AIRPORT IN PERSON WITH HIS GREEN-ANDBLACK ROLLS-ROYCE TO GREET MANY OF HIS ILLUSTRIOUS GUESTS, INCLUDING LIBERIA'S PRESIDENT WILLIAM V . SHADRACH TUBMAN, WHO ARRIVED FIVE DAYS EARLY SO AS TO SQUEEZE IN A STATE VISIT . THE GUEST LIST WAS A WHO'S WHO OF AFRICA'S SUCCESSFUL REVOLUTIONARIES AND MODERATE NATION BUILDERS . GHANA'S EGOCENTRIC OSAGYEFO (REDEEMER), KWAME NKRUMAH, WAS DUE IN FROM ACCRA . FROM THE CONGO WOULD COME THE EMBATTLED PREMIER CYRILLE ADOULA . ALSO ON THE LIST : NIGERIA'S ABLE PRIME MINISTER SIR ABUBAKAR TAFAWA BALEWA ; SENEGAL'S SENGHOR ; GUINEA'S SEKOU TOURE ; AND DOZENS MORE, INCLUDING, OF COURSE, THAT AFFABLE FELLOW FROM UP NORTH, EGYPT'S GAMAL ABDEL NASSER, WHO WAS AN AFRICAN OF A KIND . PREDICTABLY, THERE WERE THOSE INTERESTED IN BENDING THE CONFERENCE TO THEIR OWN ENDS :. GHANA'S NKRUMAH SENT A 120-MEMBER DELEGATION PILING INTO ADDIS ABABA COMPLETE WITH A HIGH-LIFE DANCE BAND . OSAGYEFO WOULD BE PEDDLING HIS PET SCHEME FOR A BICAMERAL ALL-AFRICA PARLIAMENT AND OTHER SIMILAR QUICKIE APPROACHES TO A UNITED AFRICA . NO ONE WAS LIKELY TO BUY NKRUMAH'S SCHEMES, HOWEVER, FOR IT HAS LONG BEEN OBVIOUS TO ALL OF AFRICA THAT IT IS BASICALLY NKRUMAH THAT NKRUMAH WANTS TO PROMOTE . APART FROM THAT, REGIONAL DIFFERENCES MAKE IT CLEAR THAT THE MOST THAT CAN BE ACHIEVED IN THE FORESEEABLE FUTURE IS A LOOSE ASSOCIATION OF AFRICAN COUNTRIES PATTERNED AFTER THE ORGANIZATION OF AMERICAN STATES, WITH A PERMANENT SECRETARIAT, COUNCIL AND PROGRAM FOR ECONOMIC COOPERATION . SUCH A GROUPING MIGHT HELP HEAL THE RIFTS AMONG THE CONTINENT'S CURRENT RIVAL BLOCS CHIEF AMONG THEM THE LEFTLEANING CASABLANCA GROUP (GHANA, GUINEA, MALI, MOROCCO, ALGERIA, EGYPT), AND THE MORE MODERATE MONROVIA GROUP, NOW COMPOSED OF NIGERIA, LIBERIA, SIERRA LEONE, ETHIOPIA, THE FORMER BELGIAN CONGO, AND MOST OF THE FORMER FRENCH DEPENDENCIES .