CONVERSATIONS WITH AMERICANS, by Mark Lane, 247 pages, Simon and Schuster, $6.95.

WHEN I came home one summer, I wandered by the baby contest that was being held at the Band-shell, my town's coquina-rock version of the Hollywood Bowl by the Atlantic Ocean. There, costumed boys and girls two and three years old were given their first taste of the footlights, the heady liquor of performing for an audience. The three winners in the boys' division that year were dressed as an Indian, a cowboy, and the last wore a minutely detailed copy of a Special Forces uniform. A sweating man in tuxedo lined the three up in front of a battery of Chamber of Commerce and news photographers, whereupon the contestants blinked mutely like pole-axed calves as the flashbulbs burst and the shutters began snapping like a den of rattlers.

Meanwhile, the rides further down the board-walk kept spinning and dipping and whirling-the bumper cars and whirl-a-gig and Octopus. Tucked in quieter corners of this carnival, for the very smallest children, are tamer rides which turn in small circles, go very slowly, and remain perfectly level. They are designed to prevent the children from crying, to avoid upsetting them, rather than for excitement.

The little children, about the same age as those in the baby contest, are strapped in tightly and stare out at the fluorescent fuzz around them; they tend to look very stolid and serious in their little pods, like their grandparents out for a 15 m.p.h. procession to a movie or a drive-in church. After perhaps a dozen revolutions, one set of parents plucks their beloved bundle from a pod proudly emblazoned with a screaming, claws-out eagle, the stars and stripes, and the words "Cong Killer" on the side-and stuffs a thick wad of pink cotton candy in his mouth as a reward for not throwing up in his very first ride at the midway.

Just before Thanksgiving, Simon and Schuster released a book which no one will want to read while eating-Mark Lane's Conversations with Americans consists of 32 tape-recorded interviews with Vietnam veterans that dwell on acts of brutality and the psychology of the armed forces which primes our soldiers for them. Reading this book is like taking a ride in a spin-dry Laundromat filled with blood. Approximately one-fourth of the way into the book, there remains nothing for the most naive reader to discover, and the same events keep repeating themselves in wave after inexorable wave of nausea. After a cycle or two of these atrocities, all the blood has spun right out of the reader's head, the events lose all their reality, and all that's left is a grey blur of the type and the white of the page.

THE NUMBER of incidents of this nature in this book suggests that either witnessing or participating in these atrocities is part of every American combat soldier's experience in Vietnam. The interviews reveal that Americans soldiers have:

Tortured, for revenge as well as for information, Vietnamese prisoners with the following methods:

Dragging men from a rope from a helicopter along tree tops.

Attaching high voltage electrodes to the testicles of men and to the vaginas and breasts of women.

Pulling fingernails off with pliers.

Inserting bamboo splinters into eardrums.

Taking fellow prisoners to airfields, to watch suspect pulled apart in the air by helicopters, or pushed out of helicopters from a sufficient height to kill them.

Shot Vietnamese civilians, old men as well as children, for target practice, for kicks.

Poisoned children by giving them water-like cookies made of plastic explosives.

Gang raped available women, often followed by a modern version of ritual sacrifice which is accomplished by inserting a lighted flare inside the victim's vagina and watching her explode.