Between the dark and the daylight, When the night is beginning to lower, Comes a pause in the day's occupations, That is known as the Children's Hour." -- Longfellow, 1860.

On Wednesdays at twilight, the little ones gather like a flock of birds -- wearing Dr. Dentons and clutching Teddy bears -- for the Falls Church library's bedtime story hour. On Thursdays after school, the CRABs convene at the Oxon Hill library to rave about their latest bookshelf booty. On Saturday mornings, a gaggle of neighborhood children descends on the Tenley-Friendship branch library to work on a literary dollhouse, each room reflecting a favorite story.

Children and books, as a poster in the Oxon Hill children's room points out, are "encounters of the best kind," magic that can stretch horizons, uncork new worlds, take a kid places he never dreamed existed.

A child's first library can be like a first teacher, inspiring a love of learning that lasts a lifetime. What should a library children's room be? Librarians use words like "warm gay, inviting, helpful and friendly." A Silver Spring mother compared two libraries this way: "The books are basically the same. The difference has to do with whether the librarian minds the fact that children are children." A reading tutor said, "It would be nice to have a reading nook, a place that's different from the rest of the library, a cozy, carpeted, crawl-in space just for preschoolers around the picture books." A D.C. children's librarian said, "A library is for individuals, too. That sometimes gets lost in terms of programming. A library should be a place where a child can be annoymous."

Here, then, are a few (by no means all) children's rooms in the area that with a little money and a lot of imagination have fashioned a welcome climate for youngsters just beginning to discover the joy of reading.

For a small branch library, the Silver Spring mother praises the Long branch LIBRARY off Arliss Avenue (8800 Garland Avenue, Silver Spring; open Monday through Thursday 9 to 9, Friday and Saturday 9 to 5). The book selection is good, with multiple copies of favorites. The atmosphere's informal: there's a guinea pig, and the librarian's desk is bedecked with children's drawings. A box of puppets and a child-size puppet stage, crayons and sheets of paper and puzzles abound. Last summer, there was a playhouse set up in the children's room, and outdoors is the best climbing strucutre for little ones in that area. The library's usually full of middle-class and public-housing kids who live nearby. The librarians run story hours and children's films. But what impressed the Silver Spring mother most was that the librarian took the time to look at her son and ask what interested him.

For a large library, the BETHESDA LIBRARY children's room is exemplary (7400 Arlington Road, Bethesda; open Monday through Thursday 9 to 9, Friday and Saturday 9 to 5).Children's librarians Rebecca Ratliff and Barbara Norland are both knowledgeable and friendly. The atmosphere is comfortable, with wall-to-wall carpeting and reading sections for different ages. For preschoolers, there's an inviting little area with two wide steps, wood puzzles and picture-book shelves clearly labeled ABC, Counting, Mother Goose. For older children, there's a brickwalled reading area with cozy orange loveseats, plants, some modern art and sculpture that looks out on a little garden. Interesting crafts created by patrons -- a tin woodsman head, a bird made out of soda cans, a Styrofoam robot and spaceship -- are displayed throughout.

Programs include preschool storytime (Tuesdays at 10, 2 and 4), a once-a-month Saturday film for ages seven and up, penny theater, holiday crafts and sometimes a book discussion or special activity, such as a Washington Capitals exhibit and talk or a guessing grab-bag for children learning their senses. Beneath a colorful array of animal posters by Brian Wildsmith is a large choice of beginning readers, alphabetized, in good condition, and with multiple copies of favorites. Beyond county booklists, the librarians have made booklets with imaginative college covers listing books for younger, intermediate and older readers. For young mystery fans, there are 3-by-5 cards listing the library's Nancy Drews and Hardy Boys tacked above the shelf. There are also records, magazines and foreign-language books for children, and a wide variety of nonfiction -- the Ms alone cover machines, magic, minerals and music.

The MARY RILEY STYLES Public Library in Falls Church is our favorite (120 North Virginia Avenue, Falls Church; open Monday through Thursday 9 to 9, Friday and Saturday 9 to 5, Sunday 1 to 5). The name, the ambience -- even the faintly musty smell bring back the no-nonsense librarians we knew; yet the librarians are friendly and go out of their way to help. The children's room is short of frills, but has a solid collection of good books. Beginning readers are alphabetized on how shelves and clearly marked with yellow tape. My six-year-old is like the proverbial kid in a candystore in the face of so many beautiful pictures and big words he can read himself. We never seem to escape without an armload of 12 books, many in mint condition and currently on bookstore shelves. Sometimes, we sit on the carpeted steps and read in the sunlight-filled bay window or take our books to a bench in the delightful park across the street. The library holds Wednesday story hours (10:30 for preschoolers, 7:15 bedtime story for those four to seven), occasional puppet shows. There are also wood puzzles to occupy non-reading siblings, a globe and a terrific children's record collection (we like "Free to Be You and Me" and "Alligator Pie"). The librarians have prepared a list of books that help answer those difficult questions young children ask about subjects such as adoption, death, divorce and how babies are made.

When you see the happy red knitted crab, you're in the OXON HILL BRANCH LIBRARY children's room (6200 Oxon Hill Road, Oxon Hill; open Monday through Thursday 9 to 9, Friday 1 to 6, Saturday 9 to 5, Sunday 1 to 5). Oxon Hill is home to the famous CRABs -- Children Raving About Books -- a book-discussion group started 13 years ago by children's librarian Birdie Law. Currently, about 10 to 15 regulars, ages 10 to 13, meet every Thursday at 4, sometimes inviting a favorite author to speak, bestow an annual CRAB-bery Award, and prepare an annual booklist. Other programs for children include the OWLLs -- Oh, We Like Libraries! -- a craft/variety hour (Mondays at 4 for ages six to nine), preschool storytimes (mondays at 10 for age two, Wednesdays at 10 for ages three to five), holiday crafts and films, and sometimes miniature theatre. A red-white-and-blue banner trumpeted an important voting opportunity for kids during election week -- Elect Your Favorite Book. The winner was announced during National Children's Book Week.

In many ways, the library goes out of its way to make things easy for children: The preschoolers have a section near the picture books with low tables, wooden puzzles and toys, such as a Pooh-bear to share a book with. The children's room has a showcase where kids can display their hobbies for a month. There's a terrarium, an aquarium and a sand-filled glass box where hermit crabs live. The librarians have made alphabetized files full of magazine articles, newspaper clippings and pamphlets on many subjects to be checked out for school assignments. Toys and games can be checked out. Questions of the week, such as why leaves turn different colors in the fall, are posted, and the right answer will get you a sticker from the librarian. Comic books, magazines, records, foreign-language books, and the Gallaudet College series of nursery tales in sign language are available. In the dollhouse, a black father sits and reads to his children.

The D.C. Public Library system sponsors Dial-A-STORY -- 638-5717 -- a 24-hour service with a different story each week. Some D.C. libraries cater to a particular clientele -- Mount Pleasant specializes in Spanish material, the Chinese comnmunity uses Martin Luther King. A deaf librarian vists branches to show librarians how to work with deaf children, and held classes in the Benning community near Gallaudet. Libraries east of the park would have more black material.

The TENLEY-FRIENDSHIP BRANCH LIBRARY (Wisconsin at Albemarle NW; open Monday and Wednesday 1 to 9, Tuesday, Friday and Saturday 9:30 to 5:30, closed Thursday) has in Kathleen Roedder and Eileen O'Connell a seasoned librarian and a talented storyteller in a rather institutional setting. Roedder introduced penny theater in the District, and the day I visited, the librarians were doing a seasonal show for two classes from nearby Janney School. The librarians see 14 classes a week and also offer preschool films (Tuesday at 4) and story hours (Fridays at 10:30 for two- and three-year-olds), paper crafts and fingerplays.

On Saturdays at 10:30, about nine regulars, ages eight to 14, gather to fashion miniature furnishings from found objects for a big old dollhouse donated by friends of the library. They've been at it for a year. The parlor is from Little Women, the kitchen from Wilder's Little House, the attic from The Borrowers; the bedrooms from Where the Wild Things Are, The Secret Garden, Maurice's Room (the sloppy child) and Winnie the Pooh's house. The children's room also has a science table (fossils, robins' nests), National Gallery reproductions that can be checked out for a month, encyclopedias (two days), a cage of gerbils, an acquarium, magazines and records, and the kind of posters and mobiles found in libraries.