JERUSALEM, JULY 12 -- Stacks of letters and notebooks left by Albert Einstein offer a rare glimpse of the personality of the scientific genius, his often troubled personal life and behind-the-scenes involvement in world politics.

The 43,000 documents, stored in a basement library after his death in 1955, depict a sensitive man who was beset by divisive family problems and was sometimes a victim of anti-Semitism.

Unpublished letters that Einstein exchanged with Israel's first president, Chaim Weizmann, show Einstein was a committed Zionist although he often displayed an ambivalence toward Judaism.

He repudiated the religion at a young age and frequently criticized Weizmann for the way Jewish settlers treated Arabs in Palestine before the formation of the state of Israel.

Einstein introduced President Franklin D. Roosevelt to the wonders of the atomic bomb in 1939, but said the bomb might be "too heavy for transportation by air."

Other letters reveal details about Einstein's family problems, which plagued him as a young man, although they rarely appear to have distracted him from his work in physics.

Because of emotional ties to the Jewish state, Einstein bequeathed his personal papers to Hebrew University in Jerusalem. The documents, written in German, were made available to the Associated Press by the university's archives.

Most of the papers, held together with plastic paper clips to avoid damage, are travel logs and letters written to people ranging from President Roosevelt to Einstein's first wife, Mileva Maric.

Einstein had an illegitimate daughter, Lieserl, and a son who was mentally ill, according to the letters. Both children are rarely mentioned by him later in life.

Dozens of letters between Einstein and his first wife portray a stormy relationship, with frequent separations and eventual divorce in 1919, largely a result of his mother's meddling in their life.

Because of his mother's objections, Einstein delayed the wedding for years, until after Lieserl was born. "She cried like a child," Einstein wrote about his mother's reaction to the marriage in 1900. He said his mother objected because his wife was an intellectual instead of a housewife and was four years older, 25 to his 21.

Einstein's first wife, who was in his college physics class in Zurich, was also an important sounding board for the young scientist's work.

He once wrote her about nearly dropping his theory of relativity because of a simple mathematical error.

"I wrote to you that I doubt my ideas about relativity. But my concerns were based on a computing error. Now I believe it more than ever," Einstein wrote in 1901, 21 years before winning a Nobel Prize in physics for the research.

The letters include frequent complaints by Einstein of being unable to find work.

The German-born Einstein never mastered English and had most of his letters to Roosevelt translated. On the backs of his drafts, he often doodled physics formulas.

"I'm studying English, but it won't stick in my old brain," Einstein once wrote in his diary. Even in German, he frequently made spelling mistakes.

Many of Einstein's personal letters could not be read because his daughter from his second marriage, the late Margot Einstein, had requested that they be kept secret, librarians said.

But thousands of documents are to be published over the next few years. About 150 documents were included in a volume published this spring by Princeton University in New Jersey, where Einstein once taught.

Among other papers in the Einstein collection are packets of notebooks and travel diaries. In his logs from one transatlantic voyage in 1931, Einstein commented on everything from passengers' habits to the shapes of fish in the sea.

Once he apparently got seasick. In the same sentence he wrote about his study of mechanics, Einstein broke off and added, "the ship is creaking ... the doctor says older people often get sea sick. It seems to be true."

In another passage, he wrote: "Yesterday, I took a look at the ship's engine, the diesel motor. The engineer is very intelligent. The people on this ship are especially vulgar."

In one log of a trip to New York City in 1931, he complained at length about being badgered by reporters and Jewish fundraisers.

As a victim of Nazi persecution, he was drawn to the Zionist movement that founded Israel but was critical of Jewish militancy toward Arabs in the 1920s.

"If we don't find a way of honest cooperation and honest dealing with the Arabs, we have not learned anything during our 2,000 years of suffering and deserve any fate that will hit us," Einstein wrote.

Anti-Semitism apparently dogged Einstein even after he found refuge in the United States.

His employer at Princeton, Abraham Flexner, director of the Institute for Advanced Study, once canceled Einstein's plans to spend a weekend at the White House, saying he feared publicity about Einstein's presence would put anti-Semites on his trail.

"There exists in New York an irresponsible group of Nazis ... if the newspapers had access to him ... it would practically be impossible for him {Einstein} to remain in his post ..." Flexner wrote on Nov. 3, 1933.

Einstein, who had accepted the invitation refused by his boss, wrote a note to Roosevelt apologizing for the misunderstanding and later arranged to spend another weekend with the president.