Seventy years and 140,000 exposures have clicked into the past since the Christmas when Joe Steinmetz's parents gave him an amateur photo processing outfit. He had been making snapshots for a couple of months with a box camera he received on his seventh birthday, Oct. 7, 1912, but developing pictures was something else entirely.

"I remember pouring the chemicals into the film tank," the gray-haired Steinmetz recalls, "and then making these little contact sheets. And I said to myself, 'Well, this is just magic!' "

Steinmetz says this in the living room of the home he shares on Pelican Cove here with his wife, Louise. The walls are covered with her oil paintings and a few Steinmetz photographs--a jovial closeup of a camel's face ("I call this 'Keep a Stiff Upper Lip' " Steinmetz says), a portrait of Emmett Kelly in a rubbish heap ("my favorite picture"), a beach scene snapped in Florida. There are also three stacks of dry-mounted photos rather haphazardly piled against a wall. The nonchalant manner in which they are displayed and the somewhat battered condition of the prints reveal much about Steinmetz: He certainly doesn't take his photography too seriously. The two most prominent items in the room are a hologram of a girl blowing a kiss, and a lamp, the base of which holds a plant whose leaves, when touched, turn the bulb on and off.

"Is that the damnedest thing you ever saw?" Steinmetz says.

Well, not quite. The prints lying on the floor are much more astonishing, composing an extraordinary social document of how Americans have lived their private lives over the past half century. And the hundred or so images are but a tiny representation of the more than 100,000 negatives that are filed in green card cabinets in a closet in Steinmetz's study.

This awesome piece of history will come out of the closet on Friday when Manhattan's International Center of Photography opens a show of 100 Steinmetz photos that exhibit director William Ewing calls "the discovery of the decade." The presentation is called "Killing Time," a title used by Harvard photo historian Barbara Norfleet to characterize the action in many of Steinmetz's images, which tend to be portraits of leisured individuals who seem to have nothing to do other than idle away hours.

"Perhaps southern coastal Florida really lets you know about the secret of having money," Norfleet writes in the introduction to a book of Steinmetz photos, "Killing Time," which serves as a catalogue for the show. "It is not for power, or to determine social class, but for personal freedom."

A good example of the Steinmetz vision can be seen in the image "Longboat Key Florida 1958." It is at once a documentation of a period in time, as well as a mythologization of the Beach Scene--an artful splicing of spontaneity and formality, an unusual cross between formal photography and the snapshot, something contemporary documentary photographers often try with little success. In the Steinmetz image, one encounters a family in the midst of a surfside cookout. Dad is displaying a hot dog to Junior, Mom is breezily chatting with Sis . . . And yet the entire scene seems almost pristine: There's no sand on the beach blanket, there's no seaweed scattered about the shore. It's as if Steinmetz somehow was able to find in real life the attributes that usually exist only in imagination.

Although Steinmetz himself gags on some of the philosophical musings applied to his work, he admits that his best images often have something to do with money, sunny and funny, particularly the last. "All I want to do is make people laugh," he says.

Still, this impressive body of work "has a little more impact than he realizes," says John D. MacDonald, the creator of Travis McGee, the detective who understands the peninsular, often low-life nature of Florida as do few other characters. MacDonald lives a few miles up the coast from Steinmetz, and generally eats lunch with him on Fridays. "I suppose we've been working the same street for a long time, just different sides of it," MacDonald says. "Joe's work is very clear and specific and distinct. Some reviewers have the idea that when he looks at people on the beaches and in their back yards, he's making sport of them. Nothing could be further from the truth. He takes them on their own terms, and he's accumulated a wealth of social data."

In a sense, Steinmetz came into the world as a statistical piece of that data. He was born to a wealthy Main Line Philadelphia family, his father a metallurgy engineer who designed seamless steel tanks for high-pressure gases; his mother a pianist who studied at the Boston Conservatory. Steinmetz was listed in the Philadelphia social register, attended Germantown Academy and graduated from Princeton with a degree in English. So much for surface biography; as in many of his photos there is a more lively subtext:

"Daddy was passionately interested in stamp collecting, aviation and inventing," Steinmetz says. "To think of him as a man engaged in a standard vocation is not to understand him. He invented a way of rigging balloons over London to foil the German zeppelins during the war. There were also some less practical ones: he received a patent for torpedo shields that were to be hung from the sides of boats, which would have served absolutely no good, and a rather strange car lock, which was a strap that came up from the front axle of the car and over the hood and was padlocked to the steering wheel.

"Mother was a talented pianist from Colorado Springs, where she would ride across the mesas and practice her arpeggios. Her name was Frances Oma Fields. She tried to get me to study the piano. She'd say, 'Have you studied your hour today?' and I'd say, 'Yes, Mother.' In fact, I'd been studying a comic book for an hour as I played around on the keys. I had rhythm but no melody, although I can still play part of the 'Darktown Strutters Ball.'

"I was not a terribly good student. My great achievement at Germantown Academy was to get up in the bell tower and make a snapshot up there. I signed it, 'The boy that stood highest at GA.' Ha! It had nothing to do with academic standing, and for years afterward I thought that all these new kids were probably going to try this and get killed when they fell off the roof.

"The thing that interested me most as a child was magic. Across Westview Street from our house lived a man named Walter Gibson. He gave shows around the neighborhood. We'd pay 10 cents and go sit on the lawn and watch him perform. There was one trick he did with a V-shaped wine glass. He poured water into the glass and then made it turn red, then turn blue, and then he'd drink it. To a young boy, this was quite amazing. Well, he had a tie-in with a magic shop, and for 25 cents you got the wine glass and two red and blue celluloid filters that were the heart of the illusion. I did that trick once for a few coolies on the Great Wall of China and it worked wonders. Life becomes very boring without magic.

"When I graduated from Germantown, a lot of my classmates were going to Princeton, which was one of the reasons I wound up going there. I had three desires. One was to get into the Triangle Club, which put on these wonderful musical shows. I wanted to have a good tap routine ready, so I went to Al White's dance studio on Market Street in Philadelphia and said, 'How much to learn to tap?' They said,'Oh, $30 for a 10-week course.' I told them I didn't have much time, and I said, 'Here's $30; you feed me things as fast as you can.'

"And in a week I got into the Triangle Club. I wanted to be in the club because it let you travel, get away from school. You'd get on the train and be entertained by the alumni in whatever town it was and they'd trot out the debutantes, and the debutantes would lead you down to the station half drunk. And you'd be half in orbit and hit the next town and try your luck again.

"The second thing I wanted was a letter in high jump, which I got for jumping 2 inches above my height, which at the time was 6 feet and now is 6 feet one inch. The last thing I wanted was to get a diploma and graduate. I thought I wanted to be in the advertising business because I had subscribed to Printers Ink in high school and thought it was the most fascinating magazine. So I majored in English and thought that would help me in my career, but reading 'Beowulf' in Middle English doesn't exactly make for snappy advertising copy."

Through all this boola-boola madness, Steinmetz was snapping away at subjects he would return to later in his life. After graduating from Princeton, where he was a member of ROTC and commissioned as a second lieutenant, Steinmetz went out to a dude ranch in the Big Horn mountains above Sheridan, Wyo.--only to have his visit cut short by the death of his father. After the funeral his mother suggested that he travel to Tokyo for the World Engineering Congress, which his father had planned to attend. So he set sail on the SS President Harrison, visited the convention, traveled on the Trans-Siberian railroad, went to Darjeeling to see Mount Everest and stopped in Bombay on a matter of great urgency.

"There was a vaudeville booking agent there," Steinmetz says, "who was said to have a line on a man who did extraordinary rope tricks, particularly one that involved a little boy walking up the rope, vanishing, a man climbing up the rope in pursuit of the boy, falling into pieces, and then when the magician clapped his hands, both of them reappeared intact. I wanted to learn this trick in the worst way, and I was simply told to travel to Cairo and put an ad in the paper there.

"Well, I never found the magician, but in Cairo I saw all these photographers using little Leica cameras. That was in 1928 and I bought a Model B. Up to that time I had really been making pictures of my family and friends and my dog, an Airedale named Sudan Swiveler. But now I had a real camera. When I got back to Philadelphia I met a man named Pop Claxton, who showed me how you can enlarge photos from these 35mm negatives and I thought, 'My God, how can this be possible?" I had to have one of those enlargers and went roaming through the pawnshops of Philadelphia and found one."

Steinmetz's first use of the enlarger was to print up candid wedding albums--an idea he originated and, until now, the only recognition accorded him as a professional photographer--as gifts for friends who had just been married. He'd shoot away at the wedding preparation and continue shooting even after the bride and groom had departed, and then bind his Agfa Brovira Velvet prints into an album. An old sample still sits on a table in his living room; the spine reads, "Mary Mason Marriet to H.L. Hudson, June 22, 1935," and the first page is filled with newspaper clippings from the big day. Like Steinmetz, headlines haven't changed much: "U.S. Trouble Shooter Dispatched To Ethiopia"; "High Grade Stocks Lead Market Rise"; "Ireland Drafts Treaty of Peace With Britain."

So impressed were friends by this novel type of wedding photo that Steinmetz soon began doing a brisk business in albums for paying customers. At one society event he met Pete Martin, art editor of The Saturday Evening Post, who gave him an assignment to shoot fans in the bleachers of a baseball game for the magazine. Steinmetz thought this a silly task until Martin handed him a check for $150. "My God," Steinmetz says, "having fun and making money! I was hooked." And although he worked briefly in the advertising and insurance businesses, he continued to shoot weddings and contribute to the magazine. Perhaps half the ICP show is drawn from this period of photography, documenting the rich parading before a background of empty champagne bottles, equestrian events and well-appointed mansions.

And then along came World War II, and 2nd Lt. Steinmetz was whisked off to what he thought would be combat, since his commission had been in the artillery; instead, a friend advised him to show up at headquarters with some photo prints in hand, and Steinmetz was duly assigned to Navy photo school in Pensacola. He had been suggested for inclusion in Edward Steichen's unit, which was out on the carriers dramatizing the war effort, but instead was given the task of rewriting two technical books and teaching 5,000 draftees how to aim and shoot a camera. It was in Pensacola that Steinmetz met Bradford Bachrach, who has been a friend ever since and who first suggested to Barbara Norfleet that Steinmetz's work was worth looking into.

"We moved to Florida in 1940," Steinmetz says. "My son had pneumonia and the doctor in Philadelphia told us to take him south and get him out of the slush. Well, he just bloomed and we decided to stay here. I knew at that point that I could work anywhere as a photographer, and we loved the idea that you didn't have to dress up in a tuxedo to go to dinner. It was such a relief.

"I'd get all kinds of assignments. The Florida Development Commission sent me around the state for months to make photographs for promoting tourism. I made pictures for Tupperware, and pictures of the interiors of trailers for some magazine published about mobile homes. One time I was making a picture for a Campbell soup ad and a flashbulb exploded and they had to get rid of hundreds of pounds of butter because of the broken glass. GE, who made the flashbulb, wound up paying for the butter.

"I made pictures for Life magazine, I made pictures of Amos and Andy. I made a crazy picture for an ad for Surf detergent that had a woman carrying an elephant in a laundry basket. The thing was that you didn't need to rinse your clothes after you washed them in this stuff, and the weight of the elephant was supposed to show how much water you didn't have to lug in a month. Remember, this is before automatic washing machines. Then I fell in love with the circus here, and made pictures of Ringling Brothers for 20 years. One of my favorites is of the fat lady--her name was Alice From Dallas--eating a box of dog biscuits while she read a detective magazine. I made Emmett Kelly's Christmas card photo one year. We put him a bathtub with a couple of boxes of detergent, and put an electric beater in the tub to churn up the suds.

"I wished they had included some of the circus photos in the show. I'm not sure why they put in all these pictures of Florida. Why would people want to look at pictures of a Tupperware party? I don't think I understand it. I like humor."

There was the time, recalled by MacDonald, when Steinmetz bought an entire station wagonful of used books, stamped the name and address of a friend, Bandel Linn, inside each one, along with a request to return the book to its owner, and then started leaving the books around the country. Within two years the man's living room was three feet deep in books.

"It's typical Steinmetz," said MacDonald. "One woman wrote this poor guy a letter asking for postage to return the book. Joe has a terrific sense of humor."

Well, says Steinmetz, "of course! Is there anything better you can do with your life than make people laugh? Did I tell you that my wife and I were married on April Fools' Day?"

And with that, Joe Steinmetz pulls out a small rectangular piece of carpet, four quarters and four playing cards. He places a coin in each corner of the carpet, covers each one with a card, and proceeds to unleash an amazing sleight-of-hand exhibit. First there are three quarters under one card, then two here and two there--all of it seeming to move faster than the shutter of Steinmetz's first Leica B, which had a maximum speed of 1/300ths of a second.

"It's just as easy to take a picture," Steinmetz says.

He makes it seem as if he's right.