What was going on when I was born?

The heat is on Paul A. Volcker, the heat of a clammy Washington summer, and of television lights, and of politicians, businessmen, labor leaders and economists - few of whom believe he is doing his job quite right and none of whom professes to know how to do it much better. There is such heat on Mr. Volcker right now because as chairman of the Federal Reserve Board, he wields more power over the turbulent domestic economy, and even the world economy, than anybody else. Together with his six fellow governors of the reserve board and the presidents of the 12 regional Federal Reserve banks, he can change the direction of much that matters in the American economy. In so doing, the central bank can influence the outcome of national elections.

Bill Wareham's family wanted to see more of him. So he quit the Merchant Marine after six years of service and got a job as a supervisor trainee with Consolidated Edison last June 20 - just two days after the strike started. He has been home twice in the last 17 days. The union members are walking the picket line, but Mr. Wareham is a manager, and so he works 12-hour days at the East 74th Street generating station during the first Con Edison strike in 15 years. At home in West Hempstead, L.I., his wife, Maureen, wonders when it will end. Mr. Wareham thinks his children, Stephen, 3 years old, and Christina, 18 months, are ''a little confused'' over his whereabouts.

The New York University law school must build an extension of its library or face ''a crisis in accreditation,'' the school's dean told the city's Planning Commission yesterday. The dean, Norman B. Redlich, showed the commission a map of the library addition. The law school has proposed building it underground below Sullivan Street.

Retail sales cooled somewhat in June after strong month-to-month gains in the preceding three months, but were up sharply from the weak performance of a year earlier, according to Government figures released today. The Commerce Department said retail sales for the month rose seven-tenths of 1 percent from May and 12 percent over June 1982. The June gain put second-quarter sales 25.7 percent above the first three months of the year after adjusting for annual seasonal variations.

Canada is violating world trade rules by imposing too many curbs on foreign investors, a GATT panel ruled. The decision, in response to complaints by the U.S., noted in particular Ottawa's requirement that foreign companies buy Canadian raw materials for their manufacturing. The ruling could permit the U.S. to take reciprocal actions against Canada. (Page A1.) China and Britain ended two days of talks on Hong Kong. They said merely that more talks will be held in two weeks. (A4.)

Governor Kean demanded today that New York City stop sending displaced families from the city to hotels in New Jersey, calling the practice ''the height of irresponsibility.'' In a statement, Mr. Kean said: ''Homeless people are in need of social services, health care and employment training. All of these opportunities are being denied them by the action of New York City in stockpiling them in hotels in New Jersey.'' Mr. Kean said George J. Albanese, the New Jersey Commissioner of Human Services, would meet with officials of New York City and State next Tuesday in Newark to resolve the problem. Mr. Kean said, ''Not only does the relocation place an unfair burden on the taxpayers of New Jersey, but it is totally at odds with the needs of the persons involved.''

The Big Three automobile manufacturers reported today that sales of new cars rose by 41.9 percent in the July 1-10 period, continuing a trend of improving sales that began late in May. The Chrysler Corporation reported its sales were up 51 percent, the largest increase of the Big Three. The General Motors Corporation, the industry leader, said sales were up 48.1 percent. And at the Ford Motor Company, the No.2 auto maker, sales rose 24.5 percent.

ELLIJAY, Ga. THE sun filters in through groves of towering white oak and hemlock, and the sound of water is constant as it trickles over the rocks of Turnip Town Creek from a small waterfall and continues for seven or eight miles to the Ellijay River. It is an idyllic setting, deep in the Blue Ridge Mountains of northwestern Georgia, cosily close to the Tennessee border. The log cabin, perched alongside the creek, is remote from the main highway, reached by a long, winding, tricky and not particularly good gravel road. The cabin might almost be removed from civilization but for the small building that guards the entrance and the men who appear the moment a vehicle is heard. For this is the second home, the hideaway, of Jimmy and Rosalynn Carter, and for a former President and First Lady, privacy does not preclude the Secret Service. This is the first season that the Carters have used the cabin, built last year by John Pope, who is in the construction business, and whose wife, Betty, is a cousin of the former President. The design, though basically from a kit, includes an amalgam of details added by the two couples. The Carters and the Popes are joint owners of the 10-acre plot and the cabin, although the Popes live in another house just a neighborly drive away at the top of Walnut Mountain.

-------------------------------------------------------------------- Eleanor Perenyi is the author of ''Green Thoughts, a Writer in the Garden.'' FOR dedicated gardeners interested in the history of their obsession, the good news is that Gertrude Jekyll's books, first published between 1899 and 1918 and out of print for as long as one can remember, have been reissued this year. Those who want the complete Jekyll oeuvre (eight volumes including the classic ''Gardens for Small Country Houses'' and ''Home and Garden'') will have to choose the English edition, published by the Antique Collectors' Club. The American edition, published by the Ayer Company, is limited to five titles: ''Wood and Garden,'' ''Colour Schemes for the Flower Garden,'' ''Wall and Water Gardens,'' ''Lilies'' and ''Roses.'' The bad news is that although both editions are offsets of the originals and include Miss Jekyll's own black and white photographs, neither would meet the author's standard of production. The English titles have prefaces that are inadequate to introduce Miss Jekyll to readers who don't already know her, and are encumbered with modern photographs in color that, since they aren't identified and could have been taken anywhere, add nothing except to the cost.

Interest rates declined slightly yesterday, reversing some of the increases of earlier in the week. Investor demand for Treasury notes and bonds remained weak, analysts said, but prices rose and yields fell on speculative buying by some dealer firms. By late in the day, Treasury issues due in 10 years or more were up about a quarter point, with the 10 3/8 percent bond due in 2012 offered at 91 3/8, to yield 11.38 percent. Treasury bill rates declined less than one-tenth of a point, with the three-month issue bid at 9.08 percent.

Governor Cuomo replaced the chairman of the State Commission of Investigation and one of its commissioners today and gave the new chairman, David G. Trager, instructions to wind up the commission's work with an eye toward abolishing it next year. Mr. Trager, a Republican and former United States Attorney for the Southern District of New York and now dean of the Brooklyn Law School, replaces Lola S. Lea, a Democrat and Manhattan lawyer who was appointed by Gov. Hugh L. Carey in 1981. Mr. Cuomo also announced that he was appointing another former United States Attorney, Edward R. Korman, a Democrat, to take the seat on the commission now held by Bernard C. Smith, a Republican. Protest by Anderson The appointment of Mr. Korman brought an immediate denunciation from Warren M. Anderson, the leader of the Republican majority in the State Senate. The Senator said: ''Unless the appointment in place of Bernard Smith is withdrawn, there will not be another gubernatorial appointment confirmed during Mario Cuomo's term in office.''

In the last three weeks, Gordon Gilman has learned a harsh truth of the real estate business. It is hard to sell a house near a bridge that falls down. Contracts had been drawn up and a closing date set for the sale of his home. But then, on June 28, a 100-foot section collapsed on the Mianus River bridge here, four vehicles plummeted and three people died. The wreckage landed perhaps 150 feet from the house. ''The buyers said, 'Under the circumstances, no thanks,' '' Mr. Gilman recalled. ''And there was no way I could convince them. How do you explain a bridge falling down?''