"HICK-HICK," hollers Christy, my 15-month-old daughter, pointing at the tall-case clock, twin to the grandfather clock in her book of nursery rhymes. She wants Mommy to sing "Hickory Dickory Dock" while her little fingers scamper mouselike up and down her jumpsuit.

Christy and I are visiting "On Time," a new permanent exhibit, funded by Timex Corp., at the Smithsonian's National Museum of American History.

As I survey the 4,000 square feet of clocks and desk calendars, I can't help relishing the absurdity of contemplating time with a toddler who tends to go through life at her own sweet pace.

"On Time," which opened in November, chronicles Americans' changing perceptions and measurement of time, from the 18th-century reliance on seasonal rhythms and sun dials to today's obsession with time management and hyper-accurate quartz watches.

The exhibit is well-designed for those both short and long on time. You can pick up the small guide at the entrance and hit all the highlights in about five minutes. The curious and thoughtful, though, will find much to linger over: James Yang's contemporary clock-man sculpture, Benjamin Banneker's almanac of 1792, Helen Keller's pin-studded, touch-sensitive pocket watch, a collection of Mickey Mouse wristwatches and the skeleton of Lexington, a 19th-century racehorse whose speed inspired the invention of the stopwatch. Such objects intrigue even little ones like Christy, though the exhibit's overall focus will be grasped best by kids 8 and older.

The exhibit's five sections correspond to periods of American history when there were shifts in society's concept of time. Moving through the first three sections -- Marking Time (1700-1820), Mechanizing Time (1820-1880) and Synchronizing Time (1880-1920) -- I noticed how timepieces, initially hand-crafted rarities, became smaller, more accurate and easier to obtain. The factory-produced watch became an accessory, the alarm clock prompted promptness and trains began running more reliably.

Though the exhibit sports numerous videos and interactive computer displays, the most illuminating guides were the simple "Got a minute?" signs scattered throughout, which encourage folks to reflect on the clock's role in their lives. As Christy frolicked and demanded apple juice, I took one sign's suggestion and tried to ignore my wristwatch while becoming more aware, like her, of marking time in other ways: "I'm hungry," "It's getting dark." Families answering the questions on these signs will learn a lot about how their members think about time.

"We don't want to demonize the clock, which is a neutral technology," says Howard Morrison, an interpretive specialist closely involved in the exhibit's development. "But we're hoping to make people more aware of how they apply it to their lives." Though kids don't usually become aware of clock time until age 6, they can become captive to it fairly young because of the need to adapt to parental and day-care schedules.

Probably more than one parent will ponder the sad fate of industrial psychologist Lillian Gilbreth's "happiness minutes" in the Saving Time (1920-1960) section. Through diagrams, time-motion studies and a well-organized General Electric 1934 refrigerator, all on display, Gilbreth, the mother of 12, showed homemakers how to cook and clean more efficiently, to allow extra time for family and fun.

This greater efficiency, though, seemed to have a different effect. Over the years Americans tended to squeeze yet more activities into a day until, as revealed by the plethora of personal organizers in Expanding Time (1960-present), almost every hour had been segmented and filled, even those once devoted to sleep. Young visitors can probably relate to one teenager's busy schedule, as structured as that of a corporate CEO.

After tripping through time so quickly, I welcomed a break in the "Wait a Minute" room, where I could watch Christy literally race around the clock that is part of the floor design. As Morrison points out, "We've accelerated people's pace through the course of the exhibit. This room helps put the brakes on, at least momentarily." The room features several colorful, cozy chairs and will soon include electronic books with essays by Barbara Kingsolver and Dave Barry. Morrison suggests that families also use the space to explore their perceptions of time. Parents might be surprised at the answers kids give to questions like "Is faster better?" or "If you could add an hour to your day, what would you do?" Morrison says.

A lovely bonus was the unexpected "concert" that actually occurs every hour on the hour. Christy and I just happened to be at the exhibit when the numerous clocks struck 3. As the chimes, dings and bongs peeled forth, one after another, Christy clapped and shouted, "Music!"

ON TIME -- National Museum of American History, 14th Street and Constitution Avenue NW (Metro: Smithsonian). 202/357-2700 or 202/357-2020 (recording). Web site: www.si.edu/ nmah. Located in the east wing of the first floor, the exhibit is open daily during museum hours, 10 to 5:30. Free admission. Inquire at the museum's information desk for times when educational carts are available in the exhibit space. The carts offer hands-on activities for youngsters, including building a giant pocket watch and participating in a time-motion study.

Suggested Reading

"KEEPING TIME," by Franklyn Branley, illustrated by Jill Weber (ages 8 to 12, Houghton Mifflin, 1993, $13.95). This book is chock-full of intriguing time-related tidbits, humorous line drawings and activities, such as making a sun dial.

"LITTLE RABBITS' FIRST TIME BOOK," written and illustrated by Alan Baker (ages 3 to 6, Kingfisher, 1999, $10.95). This engaging first look at time for preschoolers includes a clock with movable hands and a story that follows several bunnies through their day -- cleaning up at 9, eating lunch at noon and getting ready for bed at 7.

"ON TIME," by Gloria Skurzynski (ages 9 and up, National Geographic, 2000, $17.95). An award-winning author examines the history of time measurement and discusses how time and space relate.

"THE STORY OF CLOCKS AND CALENDARS," by Betsy Maestro, illustrated by Giulio Maestro (ages 8 to 12, Lothrop, Lee & Shepard, 1999, $16). Full-color illustrations and an informative text bring alive the abstract concept of time. Kids may be fascinated to learn that the Babylonians in 1750 B.C. were the first to divide the day into 24 hours, with each hour divided into 60 minutes and each minute into 60 seconds.