What was going on when I was born?

The Reagan Administration and business representatives were reported today to have worked out a compromise on a sharply criticized element of the Administration's revised tax package dealing with depreciation. Administration officials said that the compromise on a formula for accelerated depreciation was likely to be announced tomorrow, one day before committees in both the House of Representatives and Senate are scheduled to start drafting their respective bills. However, aides to Representative Dan Rostenkowski, the Illinois Democrat who is the chairman of the House Ways and Means Committee, said it was uncertain whether the panel would start ''marking up,'' the process of drafting a bill, on Wednesday. 'Discussion' in Senate The Senate Finance Committee, evidently to discourage delay in the House, scheduled a ''discussion'' of the tax bill for Wednesday with Treasury officials. The term ''discussion'' meant that no votes would occur, but it was plain that the Senate committee, under a Republican chairman, Bob Dole of Kansas, would be starting its consideration of a tax bill.

Two Toronto investment dealers announced plans today for a merger that will create the largest investment firm in Canada, with a staff of about 1,800, offices in 29 cities and combined revenues of more than $200 million (Canadian). The new firm, Dominion Securities Ames Ltd., will combine Dominion Securities Ltd., ranked No.2 in capitalization among Canadian firms, and A.E. Ames & Company, No.8. According to Anthony S. Fell, president and chief executive officer of Dominion Securities, who will hold the same positions with the combined company, Dominion Ames's combined capitalization of about $50 million will make it ''about 20 percent bigger than Wood Gundy Ltd.,'' the Toronto firm that now ranks No.1 in the industry. Mr. Fell and Robert E. Bellamy, Ames's president and chief executive officer, who will be deputy chairman of the new company, said in response to questions at a news conference that once the merger, planned for Aug. 1, takes place, there are likely to be reductions in staff.

The United States ''condemned'' Israel today for bombing an Iraqi nuclear reactor and said Israel may have violated its aid agreement with Washington by using American-made warplanes in the attack. In the harshest criticism of Israel by the Reagan Administration, the State Department also said that ''the unprecedented character'' of the surprise raid ''cannot but seriously add to the already tense situation in the area.'' With Iraq calling for a pan-Arab meeting to discuss the ramifications of the Israeli attack, there was concern within the Administration whether President Reagan's special envoy, Philip C. Habib, would be able to continue his efforts to settle the crisis caused by Israel's threat to attack Syrian missiles in Lebanon. Mr. Habib, who flew to Paris Saturday, had planned to go to the Middle East today, with Israel his first stop, officials said. But State Department officials said that because of the raid, Mr. Habib was still in Paris, waiting for the political storm to pass.

The Supreme Court today handed a defeat to the Internal Revenue Service, ruling by 6 to 3 that the meals and lodging provided for thousands of workers by their employers were not ''wages'' for the purpose of computing Social Security and Federal unemployment taxes. Such benefits are not subject to income taxes when they are provided for the convenience of the employer. But present Treasury regulations include the value of meals and lodging, even those not subject to income taxes, as part of the wage base for the Social Security tax, levied under the Federal Insurance Contributions Act, and the unemployment tax, levied under the Federal Unemployment Tax Act. That interpretation was challenged by Rowan Companies, an operator of offshore oil drilling rigs in the Gulf of Mexico. Workers stay on the rigs for 10-day shifts and receive food and living quarters there worth about $6 a day. Rowan did not pay the Social Security or unemployment taxes on these benefits and, after an audit, was assessed $35,000 in unpaid taxes.

Reductions in the price of crude oil continue to shake the already unsettled international petroleum markets, and further drops in price are expected. Some spot prices have plunged to $32 a barrel. Oil analysts expect this trend to reduce retail gasoline prices and, possibly, break the grip of OPEC. (Page A1.) The Administration and business representatives agreed to a compromise over a heavily criticized depreciation schedule in the President's scaled-back tax package, according to reports. An announcement is expected today. (D1.)

AN American mathematician has discovered in an English library a manuscript containing more than 600 equations that represent some of the final work of Srinivasa Ramanujan, one of the giants of 20thcentury mathematics. ''The manuscript looks chaotic, even by mathematics standards,'' said Dr. George E. Andrews, chairman of the mathematics department at Pennsylvania State University, who found and identified the material - 140 pages of scrap paper, unlabeled, with an outpouring of numbers, letters and mathematical signs scratched across them. Some of the equations are crossed out; others almost illegible. But Dr. Andrews said last week that he was convinced the manuscript was prepared by Ramanujan as he was dying of tuberculosis in 1920 and was apparently attempting to work out a unifying theory that could have been a major mathematical achievement. ''The scrawl is distinctive,'' Dr. Andrews said, ''and so is the mathematics.''

LOS ANGELES PAUL MACCREADY, the California physicist who proved in 1977 that human muscles alone can power an airplane in sustained flight, plans to try shortly to prove that sunshine alone can propel a plane from Paris to London. The Solar Challenger, an airplane weighing 210 pounds without the pilot, is scheduled to attempt the 200-mile flight sometime during a three-week period beginning Sunday. ''It depends on the weather,'' said Dr. MacCready, head of the team that designed the Solar Challenger, as he made final preparations for the flight. The upper surfaces of the wings and tail of the Solar Challenger are covered with photovoltaic cells like those used on many space satellites to generate electricity in orbit. The cells, Dr. MacCready explained, will convert the energy of sunlight that falls on the aircraft into electricity, powering a motor - actually, two tiny motors in tandem - that will turn the plane's propeller. Without enough sunlight, the craft cannot fly.

BOSTON IN the summer of 1965, when she was 6 years old, Donna Williamson cut her hand on a broken milk bottle. During her hospital stay, which she disliked intensely, there was one pleasure: the kindness shown to her by an attentive college student working as a volunteer in the hospital. Late last month Miss Williamson was one of 161 graduates who received the degree of Bachelor of Science at Wheelock College here, and one of a record 20 percent of graduating seniors whose major subject dealt with helping children through the emotional trauma of a hospital stay. Miss Williamson's reasons for choosing ''Children in Health Care Settings'' as her major were personal. But most of the 30 others who selected the same major agree with her that there is a growing need for such a specialty. Officials at Wheelock, founded in 1888 to train teachers for younger children, think more and more hospitals in the United States are coming to much the same conclusion.

''For a long time, we have followed with grave concern the construction of the Osirak nuclear reactor.

The Supreme Court, in a decision likely to encourage a new round of sex discrimination lawsuits, ruled today that women who are paid less than men are entitled to sue their employers, whether or not the jobs performed by the two sexes are identical. Ruling 5 to 4, the Court held that the Civil Rights Act of 1964, which prohibits discrimination in employment on the basis of sex as well as race, is not limited to claims of ''equal pay for equal work,'' the standard adopted by Congress a year earlier in the Equal Pay Act of 1963. The decision affirmed a ruling by the United States Court of Appeals for the Ninth Circuit that gave matrons at a county jail in Oregon the right to sue the county under the Civil Rights Act. The matrons guarded female prisoners and were paid some $200 a month less than the deputy sheriffs, all men, who guarded the male prisoners. While the jobs were similar, they were admittedly not equal, and the trial court dismissed the matrons' lawsuit. It ruled that the Civil Rights Act allowed only those suits that could meet the ''equal pay for equal work'' standard of the Equal Pay Act.

The Soviet Communist Party has told the Polish leadership that it is not acting resolutely to stem a tide of counterrevolution and warned that Soviet-bloc countries ''will not leave Poland alone'' in its crisis, reliable Polish party sources confirmed today. The warning, in a letter from the Soviet Central Committee to the Polish Central Committee, was the first such official notification in the 11-month-long Polish crisis. Meanwhile, Government negotiators met for five and a half hours with leaders of the Solidarity trade union movement but made no apparent progress in efforts to avert a two-hour warning strike called for Thursday in four northern provinces. Lech Walesa, Solidarity's leader, returned from Geneva and promptly began to use his influence to untangle the dispute, which centers on the union's charges that the Government has failed to investigate an incident of police violence in Bydgoszcz last March.

In a recent two-hour interview, Police Commissioner Robert J. McGuire talked with Barbara Basler of The New York Times about the strengths and weaknesses of the Police Department and his hopes for improving it. Following are excerpts from the interview: Q. How would you rate the efficiency of the Police Department? MR. McGUIRE. Without taking credit myself, I think the efficiency of the department in terms of management is very good. I think this agency has traditionally been well-managed by very, very competent people. And you have a dedicated group of police officers, who are doing the job. With a vastly reduced work force -over 9,000 fewer police officers - we are by and large holding our own with respect to the number of arrests we're making. We're responding to at least as many 911 calls as we have traditionally done with a vastly larger Police Department.