BEHIND THE glass of a display case in the Rotunda of the Corcoran Gallery of Art, where "Thinking Inside the Box: The Art of Andrew Krieger" is now on view, you'll find a curious, yet curiously apt, message.

"Are you in again a Hurry?," reads the typographically -- not to mention syntactically -- irregular fragment of text. "I WANTED Again to explain something to you."

These gently chiding words, taken from one of several "mail poems" by the Washington-based Krieger, peek out from behind tiny windows the artist has cut into the front of an ordinary envelope, which appears to hold a typewritten letter. Except for those few visible bits of apparent correspondence, the envelope's contents are private. It's as if we've been allowed a selective glimpse into someone else's thoughts, a glimpse from which we have been invited to take a meaning other than that which was originally intended. That meaning, at least in this case, is explicit: Slow down, we move too fast.

There's little danger of speed reading here. The degree to which "Thinking Inside the Box" plays with the tension between the revealed and the concealed, the seen and the unseen, the imagined and the real, is such that those with short attention spans are bound to be frustrated.

The rewards of this show, and they are many, are for those with the patience to stoop and squint, to linger and pore over Krieger's enigmatic poems, drawings, prints and box constructions, more than 100 of which have been crammed -- that's too strong a word, I'll admit, but the show, like Krieger's art, is anything but spare -- into the Rotunda.

One of the artist's abiding fascinations, along with a certain affection for the accouterments of a bygone time and the culture of the working class, is the theme of communication. That, and what one might call its discontents. Snatches of fake advertising, cryptic signage suggesting the initials of trade union names, bits and pieces of German and stray phrases of only partly legible English pepper his works, many of which take the form of 3-D environments built inside small boxes and biscuit tins that one must bend down to see. Inoperable radios (or things that look like them) also crop up, as do mysterious signaling platforms, something called the "World Information Center" and a variety of "poetry corners," "poetry kiosks" and "poetry booths," all of which are meant, it seems, for the consumption or creation of verse. Some of these latter chambers have been installed at a place called, onomatopoetically enough, the "Blap Club." (Think the sound of flapping lips.) "There's got to be a certain amount of confusion and chaos," says Krieger of his art, and of the static he has deliberately built into it. While admiring the posterlike, text-based work of artist Jenny Holzer, Krieger prefers to scramble his own transmissions with a kind of visual interference.

If it speaks, then, it is not with the directness of a bullhorn, but with the oblique slant of mumbling, overheard dimly through the wall of the apartment next door.

"I feel like my pieces are work," says Krieger, who, in his careful choice of words, surely alludes both to the labor-intensive act of making and to the investment of effort he asks of his audience.

There is a sense in all his work of something fugitive, of something that is there and not there simultaneously. Whether it is in his designs for archaic rural structures in a place he calls "Deep Ellum" (a place in Krieger's imagination that shares nothing but a name with the real-life Dallas nightclub district), or in his found-object assemblages that pay homage to the death of the typewriter and other forms of handicrafts, Krieger's art seems to concern itself less with presence than with a kind of vanishing. In other words, his images of rural waiting stations, bus terminals and watchman's stations, along with the rest of his largely unpopulated tableaux, might be read as stage sets for a Tinytown production of "Waiting for Godot."

Along with Beckett, other artists are called to mind by Krieger's work. Joseph Cornell, to be sure, but also Carroll Dunham, Saul Steinberg, Ben Katchor and the filmmaking Brothers Quay, each of whom is evoked, in turn, by Krieger's sober and at times disturbing whimsy.

What Krieger's art most recalls, though, isn't a who, but a when.

An old-fashioned artist (in the best sense of the word), Krieger is concerned, above all else it seems, with time. The times we live in and the times that are gone forever; the 20 minutes it takes to get up in the morning, and the time we have left on earth; the time it takes to write (or read) a letter and the time it takes to make (or digest) a work of art.

As Krieger notes, a wise man once said, about the power of mark-making (in this case, by a printing press): Give me 26 soldiers of lead, and I will conquer the world. While the origin of that epigram has been variously attributed to Johann Gutenberg, Alexander Pope, Benjamin Franklin and Karl Marx, Krieger likes to point out that its fundamental truth hasn't changed, even in this age of voice-mail, e-mail and text-messaging.

Whether the mark in question is the imprint on paper of a typewriter key, an inked metal plate or a pencil lead -- or of a magnetic particle on a piece of recording tape -- Krieger's art, which reminds us that "digital" can also refer to our own five fingers, may not conquer the world, but it subtly alters it.

Not by polemics, however, but by poetry.

THINKING INSIDE THE BOX: The Art of Andrew Krieger -- Through Nov. 15 at the Corcoran Gallery of Art, 500 17th St. NW (Metro: Farragut West). 202-639-1700. Open daily (except Tuesdays) 10 to 5; Thursdays to 9. $6.75, seniors $4.75, students and guests of members $3, family groups $12, children under 12 free. Admission all day Monday and Thursdays after 5 is "pay as you wish."

Krieger's work can also be seen as part of the following group exhibition:

ON THE LINE: Machines, Maps and Memory -- Through Sept. 11 at Maryland Art Place, 8 Market Pl., Ste. 100, Baltimore. 410-962-8565. Open Tuesday-Saturday 11 to 5. Free.

"Poetry Booths at the Blap Club," from the Corcoran's "Thinking Inside the Box: The Art of Andrew Krieger."