A tiny exhibition at the American Institute of Architects reveals that in the 60 years since Time magazine was founded, 14 architects have graced its weekly cover. Out of more than 3,000 issues, that isn't a whole lot. But looking at those 14 not-so-famous faces provides a dizzying, condensed perspective on the time covered by the show.

In this period, architecture, the one inescapable art, has been sorely tested. Whether architecture has responded valiantly and successfully to the challenge is still a moot point. But there is no mistaking the fact that in this time the physical face of the world has changed more than in any equivalent period in history.

The sheer quantity of buildings destroyed and erected is awesome. The variety of new buildings--in size, type, technology and style--is unprecedented. One can debate the worth of these vast changes, but no one can sensibly argue that in terms of the vastness of architectural changes the 20th century is not unique.

The Time cover list is by definition a popular, unsystematic summary of the period. Even so, there is a certain accidental logic to the list, for by total happenstance Time's founding coincided with the Modern movement's first great burst of energy. The list begins with Ralph Adams Cram, the ardent medievalist, and William Adams Delano, one of the last of the Beaux Arts breed, and it ends with Philip Johnson in his latter-day reincarnation as an exuberant post-modernist.

In between, the Time stories touch impressionistically upon the impressive achievements, large mistakes and imperious egos of leading Modernist architects (Le Corbusier, Eero Saarinen, Richard Neutra, Wallace Harrison); of early modifiers of the International Style (Edward Durell Stone, Minoru Yamasaki); of great, idiosyncratic figures (Frank Lloyd Wright, Buckminster Fuller); and, not least, of architects whose chief contributions lie in large-scale organization and planning (Edmund Bacon, William Pereira, Nathaniel Owings).

Though they celebrated prominent conservatives of the day, the articles on Cram and Delano were occasioned by the beginnings of the great debate over Modernism. Cram did Gothic churches and Gothic universities. Delano (of Delano & Aldrich) did Georgian mansions for the rich, and public projects such as the office building with its crescent shape facing 12th Street in the Federal Triangle, in the classic revival style.

These were just the sort of buildings thought to be irrelevant by "fiery" modernists such as George Howe (of Howe & Lescaze), who was quoted at length in the Delano article. "The modern movement," Howe said, "is a conscious effort to direct and canalize the stupendous energy of modern civilization . . . The Modern architect has created a new style based on the old common law of architecture reformulated to meet modern needs in the light of modern economic and engineering genius."

Little wonder that the author of the Time story modestly concluded, "With such various schools, the architecture of the future might be any man's guess." It is ironic that today, with architecture again in a state of creative ferment and cross-fertilization, one might say exactly the same thing.

Today, though, we can repossess neither the Time writer's naivete' nor Howe's zealous confidence. Modernism was victorious in the years after World War II, so that today we can appreciate its colossal limitations as well as its significant contributions.

It seems obvious today, for instance, that despite its undeniable high points, Modern architecture, in alliance with the contemporary economic genius, has produced mediocre buildings and dispirited environments on an unprecedented scale. For every Ronchamp chapel (Corbusier) or Dulles Airport (Saarinen) or Lever House (Skidmore, Owings and Merrill) there are acres and acres of cheap commercial construction lacking any conviction other than fast profit. But by now this is an old story and one repetitiously catalogued (in, among many other places, Robert Hughes' incisive account in the 1979 Time cover story on Johnson).

What most impressed me, confronting that wall of Time covers in the lobby of the AIA headquarters, is that architecture is not so much the story of the progress of the individual genius (even on the level of Wright or Corbusier) as it is a vast collaborative enterprise. Owings, an organizer extraordinaire and pragmatist turned visionary, said this, in the cover story devoted to his firm:

"We are going to reach the point where environment planning will be the supreme thing in this country. It will be the equivalent of the railroad and highway booms. Then perhaps we can change and begin to build as did the Romans, the Greeks, the Persians, the Egyptians--begin to build a real environment that is a lasting investment rather than something to be destroyed."