BROWSING THROUGH an English junk stall a few years ago, Colin Gordon came across a collection of glass photographic negatives. Mildly curious, he bought the lot for the equivalent of $10, lugged it home, and found himself with 650 pictures of harbors, country lanes, castles, cottages and family groups, mostly dating from the turn of the century. His curiosity switched into high. Led by a single clue, "Atkinson, Huby," he divided his free time between detection and enalrging. Both were amply rewarded.

Atkinson, Alfred, proved to be a building contractor in Leeds; Huby was the dormitory village where he kept his family. These bare facts led in many directions. An Atkinson daughter (first seen as a sunbonnet baby) had just died, an eccentric spinster, in the house at Huby. Another daughter was unearthed, alive; then a genealogically minded grandson, a cousin, friends, servants. Records of the photographic society Atkinson belonged to surfaced, as did ancestral account books, building plans and, in the empty house, the skeleton of a cat long ago locked in a cupboard.

Gordon printed plates and enlarged them; he searched for extinguished beauty spots industriously recorded during long-ago summer visits, at first in horsedrawn carriages and later in a series of motor cars that culminated in a rich man's Lagonda. The Atkins had come up in the world in two generations, though by the time Alfred died in 1945 the fortunes of his business and family had coasted back down.

Colin Gordon has found out more about them than an outsider may wish to know, yet not enough. Alfred and his wife Polly, daughter of a local cabinet maker, conducted resolutely extrovert lives, leaving no trace of inviting human quirks of mind. Polly's chief oddity was her wig. Her daughter told Gordon she had cut her hair short when young and afterward wore a "transformation"; a maid was more factual: she was "bald as a plate of lard." This lends a tiny frisson to studies of Polly pensive in the garden under a wodge of artificial hair; or more recklessly dressed for a picnic or a tramp with a great windmill of a hat pinned to the wig. Alfred, a genial husband and father, perversely looks like a con man or a wife poisoner: the eyes that twinkle behind little round spectacles are more shrewd than mirthful, and masked by the neat goatee the mouth is cunning.

An old-fashioned railway carriage parked at the bottom of the garden makes a surreal background for an arresting family scene in which Polly, seated among wildflowers, dandles a new baby while her father nurses a gun. Another luminously strange photograph comes from the interior of the car, where Polly sits with friends and family (one of them again armed with a gun), each impressing his personality on the obedient camera. These are truly speaking likenesses, perhaps because the subjects are all waiting for the click to burst out talking.

No other photograph has quite this bizarre charm, but there is oddness and charm to spare: infants in huge frilled bonnets and lace petticoats toddling at water's edge, a winding path under summer trees where Gordon's enlarger discovers in the distance three fascinated little girls minding a baby in a pram and watching the man down the way taking a picture of his parents. Another blow-up of a scenic view reveals Clark's Temperance Hotel, on whose chilly terrace, under bare trees, a dour crowd huddles over nonalcoholic bevera ges. The sea is popular: sunny beachers, boats, fishermen, and a frowning baby Atkinson surrounded by sand tarts. The Alps appear as a snowy playground where men and women in impeccable tailored costumes throw snowballs.

Polly is never charming, though she was once young, and we see her in a garishly striped dress gripping a tennis racquet, or again, holding a kitten and grinning through crooked teeth, not quite used to grownup clothes. Her daughters, it turns out, didn't much care for her. When we come to later photographs of touring cars and read bits of Polly's diaries, recording mileages (200 a day was nothing) and the names of places they stopped to shop and consume big lunches, it's plain she rated things higher than people.

Yet charm is the chief commodity of these photographs, taken by a skilled but totally unoriginal amateur. He sought it willfully wherever he discerned something old-fashioned, picturesque, unspoiled. His village streets and country lanes are as clear of the mess people really lived in as they are of overhead wires, cars, and clamorous signboards.

The less intentional charm of the family snapshots is more substantial. Little girls smiling among the flowers, washing their feet in wooden tubs, up a tree with their teddy bears - 15 years before Winnie the Pooh - are winsome indeed, though it is sobering to learn from Gordon that 70 years later the little girls don't recall these summer days as idyllic. Life at Huby was stuffy, they were bored and may be miserable, and more than half of them grew up to be old maids. CAPTION: Picture, no caption, From "A Richer Dust"