Images speak louder than words and no image speaks louder than the human face. The American portraits on these two pages represent three ways of capturing faces: by commission (of the famous or not-so-famous face); in a pose by the photographer creating a "study" with models; or in a candid snap-shot. They range in style from Victorian, only one step removed from formal oil portraiture, to modern photojournalism with the feeling of action caught and preserved.

Nearly 15 years ago, in an inspired act of babysitting, Shirley L. Green - my aunt - introduced me to the Library of Congress. I was about 10 years old at the time. She took me to the Prints and Photographs reading room, with its high marble walls, and sat me down on a low stool in front of an open file drawer.

"Have fun," she said, and went off to her work as a free-lance picture researcher. That meant she spent her time finding just the right illustrations for things like documentary films and books.

I tentatively pulled out the first black-and-white photo, mounted on a heavy gray card. Staring back at me was a family standing in front of an old, fallen down farmhouse. The family looked careworn, a little ragged and yet proud - even to the smallest child (who was probably about my age). A sea of dust seemed ready to engulf the entire scene.

I continued poring over the pictures, all from the acclaimed Farm Security Administration collection (1935-44). Curiously, all I could think of was wanting to climb the wooden porch in the photo and sit next to the woman peeling potatoes. I wondered what those somber children were saying as they played with their puppies. And that front door hanging on its remaining hinges: what was inside? What was cooking for supper?

Some hours later, as we left the library, my aunt asked what I thought of the pictures.

I wasn't sure I could put the feeling into words, but I tried: "I got lost."

Getting lost in photographs continues to be my aunt's occupation and my fascination. We teamed up again recently and set out on a voyage of discovery through Washington - the nation's photo album.

The capital city houses 280 photographic archives. We chose to concentrate on two: the Library of Congress and the National Archives. Together they contain more than 15 million items (one-fifth of the city's holdings), which document the history of the world, as well as the history of photography, since the invention of the daguerreotype in 1839.

These pictures are the source for "Photodiscovery," a five-part series beginning today in this magazine.

Our search for a sample of Washington's finest, most historic and least-known photographs began in the courtly atmosphere of the Library of Congress' Prints and Photographs reading room (P&P). Their collection, built from copyright submissions, purchases, exchanges and gifts, ahs been called the country's largest and most comprehensive.

The Prints and Photographs reading room contains files that are open to the public. They include the FSA series, the Mathew Brady Civil War pictures, and the "single picture file," a whimsically random collection of subjects such as railroads, bicycles and Bibles. Also available are the geographic files, with pictures of Washington landmarks and neighborhoods and a group of stereographs complete with a stereopticon viewer for an adventure in 3-D. (The stereopticon and other processes are explained in the captions accompanying our photographs.)

These are the most popular of P&P's collections. As a result, the public has tended to fasten on a few of their most widely distributed images. Arthur Rothstein's "dust storm" and Brady's Lincoln portraits are called for and published constantly.

To go beyond the obvious and get a look at the pictures store in the library's stacks, we consulted the card catalogues ringing the P&P reading area. The curators at Prints and Photographs are pioneers in the art of cataloguing visual material and have sorted much of their holdings into lots, by subject, photographer and place. The resulting catalogue cards describe lots containing from five to several thousand photos.

A request to one of the reference librarians brings the explorer a box of neatly captioned photos. If you're lucky. Sometimes there are no captions at all. At other times the photos have faded beyond use. Then again the "views of Florida 1913" might come in a handsomely bound leather album, with hand-marbled endpapers and gold lettering.

Of course there are numerous other methods for getting at the library's collections and the story of photography's first con man, Platt D. Babbitt, daguerreotypist, came from P&P's restricted cache of early and valuable photos. (More on this one-man tourist trap June 24). The first successful color process, autochrome, is represented by more than 300 glass plate transparencies of a quality that is hard to duplicate by modern color methods.

The "78,000 glass plate negatives and an approximately equivalent quantity of photoprints in albums" of the National Photo Company, Washington's first photo news service, also make their home at the library. These photos capture everyday life in official and unofficial Washington from 1912 to 1932; a liberal sampling appears in next week's installment.

Frances Benjamin Johnston, Washington's and America's first female photographer, left her life's work to P&P, and no "photo-discovery" in Washington could be complete without a selection from her studies of labor and schoolchildren. Both of these will be represented in the section "How We Lived," in The Magazine of June 24.

The Master Photographs section of the library preserved the albumen prints of Thomas Annan of Scotland in the 1860s. His brooding view of a Glasgow alley appears in our collection of foreign photographs.

A recurring rumor has it that hundreds of photos are moldering under the eaves of the library's attic, "lost" to the curators, though occasionally "found." Jerry Kearns, chief reference librarian, denies this: "There's some reference to everything," he said recently, "in the files or the accession books." References also abound in the heads of the over-worked curators who handle the as-yet-uncatalogued material, one third of P&P's collection. The more you search, the more there is to see.

The second source for our "photodiscovery" was the National Archives. Its Audiovisual Archives Division, located in the upper reaches of the Archives building, is the repository for the pictorial records of the U.S. government. In keeping with its mandate, Archives is required to keep the records in the order in which they were arranged by the federal agency that produced them.This means that the photographs are not sorted by subject.

How, then, to begin at Archives? The key to the Pandora's box is the division's guide to the "record groups." A typical record group is RG 115, Records of the Bureau of Reclamation, 1897-1944 - 75,089 items. These include "Photos documenting activities of the bureau in the development of power and irrigation projects . . ." This may be a daunting and uninspired description. But tucked into this record group were two particularly lyrical photos in today's accompanying section devoted to the American Indian.

"If you know the mission of the agency, then you'll find what you want here," says Jim Moore, director of the Audiovisual Archives Division. By paying attention to the descriptions of the agencies whose records are preserved at Archives, stretching the imagination a bit and, of course, consulting the staff, the great legacy of the bureaucracy can be tamed - and exploited.

Archives' files of the Public Housing Administration included an unexpected photographic inventory of the contents of the pockets of lodging house boarders. We were astonished to see the variety and number of weapons apparently carried by the working man of the turn of the century.

A number of pamphlets or mini-catalogues also have been compiled by the Archives staff directing researchers to a select few pictures on topics such as "The City" or "The Navy." But as in the Library of Congress, resorting to the familiar means missing the pleasure of the conquest of the unknown.

By the end of our voyage of photodiscovery we had come to define the terms as follows: A photodiscovery is a little-known photo of a well-known figure. It is a representative of an important but underused Washington collection. It is a document of forgotten history, an obsolete social custom an out-of-fashion bit of entertainment. It is a work of photographic art or a spot of frippery. It has never been published, or it has been seen only rarely by a small audience. It deserves attention. And it's well worth getting lost in. CAPTION: The cover photograph of fin-de-siecle beach-strollers is a 1907 autochrome by Arnold Genthe. From the Library of Congress.; Picture 1, Madonna and Child x 4 George Grantham Bain Collection (far left) Modern photojournalism is the descendant of the work of reporter Bain, who used to send something extra with his stories: photographs. Newspapers used photos as models for engraved wood line drawings. In 1987 the New York Tribune's Stephen Hogan refined the half-tone process. In 1898 Bain opened the Bain News Service, setting the style for picture services and the news snapshot. These women were probably queued up to see a New York Public Health Service pediatrician when a Bain photographer came by. Library of Congress; Picture 2, Aphrodite, Arnold Genthe, ca. 1910 This study, typical of the Art Nouveau Fascination with the ancient world, is an example of the first successful color photographic process, autochrome. Arnold Genthe, whose collection now resides in the Library of Congress, pioneered the use of this process, which consisted of a glass plate coated with potato starch grains dyed red, blue and green and topped with a light-sensitive emulsion. The processed plate gave a positive color transparency. Before the autochrome process was invented in 1970, "color photography" relied on a three-plate process (for each of the colors mentioned above) or were hand-or machine-colored prints or lithographs. Library of Congress; Picture 3, Eleanor and Eskimo From the Library's Look Magazine collection, a recent acquisition. Library of Congress; Picture 4, The Lady in Blue, Arnold Genthe, ca. 1910, Library of Congress; Picture 5, Frederick Douglass and grandson Douglass, runaway slave, author, abolitionist, Lincoln adviser, minister to Haiti, reformer, humanist, also campaigned against capital punishment and mistreatment of Chinese immigrants and American Indians. The influential leader's last speech was for a new cause: women's rights. This portrait, ca. 1885, has never before been published. Library of Congress; BLACK AMERICANS With the end of the Civil War, the first flush of freedom for American blacks quickly degenerated into quiet struggles and disappointment. Some of these photos simply reflect black aspirations. Others endure for the dignity of their subjects under, in some cases, terribly humiliating circumstances. Some were discovered by looking at files identified as "Black Americans - Studies." Others turned up as footnotes to files of other subjects such as "war," "work," "children."; Picture 6, One can only wonder at the humility with which the subjects posed. Yet, many of these photographs also bear witness to enduring human strength and art, as in "Gone and de days," Library of Congress; Picture 7, Prejudice of an Era The caption to the photo below read "Both puzzled" when the photograph below was submitted for copyright in 1902. An example of the genre known as "colored comics," these tableaux - and the Library has hundreds - were supposed to be funny. Apparently at the turn of the century images of black stereotypes were considered entertainments, as well as reassurance for the reactionary. Library of Congress; Picture 8, Woman at Tuskegee Institute, 1903 (opposite) Frances Benjamin Johnston The eloquent portrait was taken by America's first successful female photographer, whose career lasted from 1888 to 1952. Her studies of Booker T. Washingtonhs Tuskegee Institute, both prints and negatives, are at the Library of Congress along with garden studies, industry surveys, and photos of the Theodore Roosevelt Wite House. Library of Congress; Picture 9, DuBois' Dream W.E.B. DuBois is credited with selecting the photos for the "Negro Life in the United States' exhibit at the 1900 Exposition Universal in Paris. Unlike Booker T. Washington, advocate of educating blacks for work in the trades, DuBois' dream was of black participation in the professions, skilled unions, in short, the middle class. "The Bricklayers Union," Library of Congress; Picture 10, above, and "The Only Negro Store of Its Kind in the U.S." (in Chicago), left, reflected DuBois' aspirations rather than the reality of the period. Library of Congress; Picture 11, Member of the chain gang, Thomasville, Ga., 1885 (right) This photo appears in the travel album of Kr. Joseph Kirkbride. This amateur photographer's personal albums documented his very full social life and love of the outdoors and travel. Fortunately, he had a keen eye for composition and subject - and his partying pals share album space with telling images of life at the side of the road. Library of Congress; Picture 12, "A Slave," ca. 1860 (left) An unknown photographer contributed this powerful portrait to the records of the U.S. Army's Chief Signal Officer, 1860-1945. The slave's classical pose is in stark contrast to the cruel history bared on his scarred back. National Archives; NATIVE AMERICANS These American Indians should seem unfamiliar, at times odd. That's because researchers in the past have either deliberately avoided or had a hard time finding pictures of native Americans that go beyond the Hollywood stereotype of the "Noble Savage," bedecked in feathers, standing by a teepee. The pictures here, many from official government records, exhibit a wide range of perceptions of the American Indian. Picture 13, Children of the Plains ca. 1870 William H. Jackson captured these unassimilated native Americans for the U.S. Geological Survey. National Archives; Picture 14, "Dredging out and deepening the channel of the Main Imperial Canal," California, 1916 (far left) An anonymous photographer for the Bureau of Reclamation realized that including people in pictures of inanimate objects always adds interest. Contrasing the Indians' overalls, their long, hair and the dam makes for a wistful portrait of the inexorable drive for progress of the European interlopers, the builders of dams. National Archives; Picture 15, Geronimo, farmer 1895 Geronimo led raids against the invading U.S. and Mexican governments, was caught and confined to an uninhabitable reservation, and escaped again. The U.S. Army put an end to his 28-year battle and sentenced the warrier to farming and selling souvenir bows and arrows and pictures of himself at expositions and fairs. Library of Congress; Picture 16, "Chief Jembo and his tribesmen as seen in the Yuma parade, 1909" (left) Tucked away in the Bureau of Reclamation records of power and irrigation projects are photos of Indian tribes of the western United States. It seems fair to assume that the native costumes of these Yumas were a bit risque for the uptight burghers of Yuma, hence the longjohns. National Archives; Picture 17, "The Great White Father now calls you his 'brother,' not his 'children.'" - Woodrow Wilson, 1913 Dr. Joseph Dixon, pictured above with an unidentified Indian, was charged with bringing President Wilson's words to some 200 North American Indian tribes. Four expeditions were financed by Ordman Wanamaker, scion of the Philadelphia family, to "perpetuate the life story of the first Americans and to strengthen in their hearts the feeling of allegiance and friendship for their counrty."; Picture 18, Dr. Dixon brought Wilson's words on a new invention, a phonograph record, and also oversaw the photographing of hundreds of Indians. Dr. Dixon (below), in a far more candid moment, quite possibly coined the phrase "wrapping one's self in the flag." Library of Congress