NEW YORK CITY, July 30--Mayor Robert F. Wagner will journey to Washington this week-end to request federal aid for Harlem's negro poulation. This announcement was made today at the conclusion of the mayor's extensive talks here with the Reverend Martin Luther King, Jr.

Their final meeting, which lasted all day, ending just after eight p.m. this evening, produced no formal agreement, however. King told newsmen the talks had been "frank, fruitful, and friendly" but said there was no indication the Mayor would follow all his suggestions. Wagner will issue a statement tomorrow morning.

But while King and Wagner were closeted in Gracie Mansion, James Farmer, head of the Congress of Racial Equality, and John Lewis, National Chairman of the Student Non-Violent Coordinating Committee, both announced they could not endorse the call of four other negro leaders for a moratorium on demonstrations until after the November elections.

In Harlem itself, this jockeying among the negro leaders seemed all but irrelevant. Police continue to blanket the area, though they no longer wear riot helmets. Even during the day, when business is at least close to normal, it is nearly impossible to find a block on a major avenue without at least one policeman.

Along 125th Street--the primary site of last week's riot--the concentration increases notably. There is one policeman on every corner of each intersection, with patrolmen either singly or in pairs walking each block. It is not unusual to see groups of four or five police clustered on any corner.

At night there is further buildup. No policeman patrols alone; the corners of 125th Street merit groups of three, and pairs and trios walk the major thoroughfares. For the small side streets and in areas with high concentrations of taverns patrols of five and six walk the beat.

Perhaps the most striking feature of Harlem's virtual occupation is that the vast majority of the police are white. The negro patrolman is not absent but he is a signficant minority.

There is little difficulty during the day; police talk relatively freely, explain to disbelieving southern tourists that they do not know if there will be a riot that night, and smile at the girls making eyes at them. But while three white policemen cluster around two old negro men playing chess on the sidewalk of Seventh Avenue, a car with loud speakers cruises by, blaring "you have the right to vote--Don't be intimidated--you have the right to vote!" A squad car follows quietly a half block back.

At night the entire situation changes. The police stand apart from the people. For the heat there are very few people on the street--the usual escape from the five story tenement. Crowds still form, however, in front of many taverns and on many street corners.

One is conscious of the occasional shouted insult as a group of five white police pass about twenty young negroes in front of a Seventh Avenue bar. Even the passing white motorist is not immune to verbal obsenities, if he envinces too much interest in the street scene.

New York City and its people are only peripherally involved. For most New Yorkers the riots could probably have happened in another city. Only the three glistening riot helmets in the rear window of every squad car remind the City of the disturbances a small portion of it is presently experiencing.