HEN BETTY BACAL was 16, she went to high school in Manhattan, took ballet lessons, shared a bedroom with her working mother in a small apartment (her father had skipped the coop years earlier), bought her clothes at Macy's, and was resolutely stage-struck. She and her friend Betty Kalb eben got to meet Bette Davis and tell her, with pounding hearts, that they too wanted to be actresses. Betty Kalb settled down to some ordinary life, but Betty Bacal had a stranger fate. After a year of drama school, some modeling, and a part in a play that never made it to Broadway, amazing things began to happen. Diana Vreeland, seeing something better than pretty in the 18-year-old model, put her on the cover of Harper's Bazaar ; Slim Hawks, a Hollywood director's wife, showed the picture to her husband; Howard Hawks decided to make a "discovery." A few days later Betty's family gave her a gardenia corsage, lunch at Lindy's, and put her on the train to Low Angeles.

Betty's 19th birthday party was given by Elsa Maxwell. She had fascinating new friends (Cole Porter, for instance), a new name, a used car, an apartment, and a starring role in a first-rate film of a third-rate Hemingway novel. Her co-star was Humphrey Bogart. Perhaps a teen-age girl takes it for granted when dreams come true in spades; at any rate, Betty's luck didn't go to her head. In fact, she could hardly keep her head still as she trembled before the cameras -- yet even this was a plus. To control herself she lowered her chin: the seductive upward gaze at Bogart was hyped as "The Look." She was warned against a shrill voice and kept hers steady and low. The image on the screen was one of knowing, sexy cool.

The adolescent girl had never even been in love, barring a crush on Leslie Howard, much less anybody's lover. But a new development as overwhelming as her absurd fame was at hand. Bogart, 45 to her 19, in the midst of a rotten thrid marriage, a cautious, controlled man with an iron streak of common sense, began to fall madly in love with his leading lady. She responded with ardor primed by a fatherless lifetime. There were secret meetings on highways in the middle of the night; when they finally made love for the first time, it was in somebody's trailer. One night in a dinghy in a dark harbor, she got up her nerve to ask Bogart something she hadn't dared mention to anyone yet, least of all to the anti-Semitic Hawks: Did it matter to him that she was Jewish? He couldn't have cared less. They made a second movie together and it seemed she couldn't put a foot wrong as an actress; but she could and did fall dismally in a misbegotten third film with a different director and leading man.

By now her delicious illicit affair mattered more than her successes and disasters as an actress. Her family was dismayed by her passion for a thrice-married man old enough to be her father; but her mother's warnings proved groundless. Bogart was something special, and so was the green girl so eager to be part of his life. Whe met his bright friends -- writers, actors -- all of them members of a generation for whom drinking was a gallant gesture, who talked and laughed far into the night over well-fillled glasses.One of them was Moss Hart. "Congratulations on your success," he told her. "You realize, of course, from here on you have nowhere to go but down." "He turned out to be a prophet," she says not quite truly; but after the two Bogart movies her career was of little account for years.

Life was anothe story. Bogart got his divorce and they were married at Louid Bromfield's big fram in Ohio "Oh, goody!" she exclaimed. Their feelings for each other did nnot cool. He was an absolutely dependable man most of the time, sure of who he was and what he wanted, and though his drinking pained and puzzled her, it was not out of control. She became the perfect wife, the perfect pal. He had never before had a real home. She set out to make one full of friends and good times, and privacy too. His passion in life, beyond his profession, was sailing, and she gulped down nausea to be with him at sea. He had never had children; she produced a boy and a girl and discovered that motherhood, like marriage, was something she had been born to.

Bogart was a little jealous of his new son. With better reason he was also a little jealous of Adlai Stevenson. This charming, almost effeminate man attracted beautiful women as fruit attracts wasps. Betty had discovered an appetite for casues when the Bogarts protested voluntary censorship in Hollywood before the House Un-American Affairs Committee, and when Stevenson ran for president in 1952, she fiercely campaigned for him; she and Bogart even spent the ghastly election night with him in Springfield. She openly adored him, but even had Adlai been something more threatening than a seduiseur jusqu' au bord du lit, , she probably woudn't have succumbed. Bogart was a mine of pithy wisdom. "Never damage your own character. To have a love affair breaks a bond between husband and wife -- and even if your partner doesn't know about it, the relationship must be less open, so something very important will never be the same." Bogart knew he had married "Baby" out of the cradle, and was tolerant of her crushes; but her firs tlove was for her husband. "Whenever I hear the word Happy now, I think of then. Then I lived the full meaning of the word every day."

After eleven-and-a-half years of this mutual happiness and unwavering professional success, Bogart stocally died of cancer. Even now Lauren Bacall doesn't know if he knew he was dying or not. The nearest he came to letting on was when she embraced him in a moment of emotion and he said, "Don't do that, Baby -- there's nothing I can do about it." A skeleton in pain, he nevertheless came downstairs every evening -- in a dumbwaiter when he could nno longer walk -- to have drinks with friends -- Katharine Hepburn, Spencer Tracy, David Niven, John Huston, a few more controlled and loyal enough to be able to confront the specter of the man they loved and admired. On his last night Betty stated with him, held his frail hand, listened to him moving restlessly in his sleep, noticing the strange, strong odor of his corruption. It lingered long after his body was carted unceremoniously away in a sack. He was only 57 -- he would be 79 today. Her loss was only incomprehensible: almost everything she now was had been shaped by him. That it was rough for the kids didn't make things easier. Her little boy, who had never cried, said, "I know, Mommy, I know how we can surprise Daddy -- we can all shoot ourselves and be with Daddy on Valentine's day."

Bogart had always warned her against mourning -- "Once you're gone you're gone." Long before she could come to terms with grief, she began a calamitous affair with Frank Sinatra, who predictably behaved "like a s --." "Twenty years later," she says of this period, "I can see that I was trying to erase Bogie's death -- pretend it had never happened -- that he had never happened."

Admirable successes on Broadway gave her a refrehed sense of herself, but she craved a man more than applause, and thought she had found the right one in Jason Robards. She struggled to protect his ego by diminishing "the Bogie shadow" -- the Bogart revival made this harder; she struggled to stop Robards' disastrous drinking. Adlai Stevenson warned her, "Remember, Bogie was a mature man. It's not going to get better after you're married, it's going to get worse." She ignored the advice and after eight bad years and one son, gave up on her second marriage.

Throughout the '60s, while she tried to get out from under being Bogart's widown and prove that she was an actress -- as she certainly did to the enthusiastic satisfaction of audiences, critics, and her peers in the theater -- she kept losing people, people she loved best of all. Adlai Stevenson dropped dead in London; Robert Kennedy, for whom she had worked almost as fervently as she had for Stevenson, met his fate; her best-loved uncle died in his fifties. "No one I ever loved, it seemed, had had his full share of life." Worst was the death of her mother, who had been close toher all the way, encouraging, approving (though not blindly -- "you only have two feet!" she remarked at the sight of Betty's shoe collection), quietly adoring this swan of a daughter. A sense of being "nobody's child" darkened her grief and did not go away. It is part of the book's ambiguous title: being "by myself" is to be forlorn and forsaken. The people she loved best are dead, the happy part of her life was over at 32. Yet she refuses to settle for those years with Bogart; there muskt be more waiting somewhere.

Her book is "by myself" in the happier sense that she herself wrote it; though it doesn't seem so much writen as spoken in that husky, urgent, humorous voice as she uppacks the contents of a remarkably detailed memory. In spite of the cliches (Garbo's face and Hepburn's personality are both "incredible") and the unassuming style ("I was one unhappy lady"), the book packs an emotiona wallop. Hollwood never turned out a lovle story up to the level of hers and Bogie's. CAPTION: Picture, no caption, Photograph of Lauren Bacall from Copyright (c) The Collection of John Kobal; Picture 2, Humphrey Bogart and Lauren Bacall