This, people say, is a great building by a great architect.

The architect was Pietro Belluschi. Belluschi was Italian, and by 1925 when he took a draftsman's job in A.E. Doyle's firm in Portland he'd been through a terrfying stint in the Italian army during World War I, gotten a two-year engineering degree at the University of Rome, had an unsatisfactory semester at Cornell and even less fun at a mining camp in Idaho. By training, he was unprepared to be an architect. His English was unsteady. He figured he'd give it a shot anyway.

Luck arrived in the form of A.E. Doyle himself, who left. He went off to Europe for awhile. The Italian also got a break from the poor behavior of Doyle's chief designer, Charles Greene. Although reputedly talented and supposed to be in charge, Greene was asked by city officials to leave town to avoid a sex scandal.

Only 27, Belluschi rose to the occasion and hit one grand slam after another after another. He successfully finished off three major buildings that Greene had abandoned, snagged commissions for the Gothic-style library at Reed, the huge Corbett House which is now part of Lewis & Clark College, working up to the 1932 main building for the Portland Art Museum. His clients were happy. The architectural press took notice. Soon he bought out the other partners and took over Doyle's entire office.

Portland got the benefit of Belluschi running on all six inline pistons through about 1951. The Equitable, unbelievably, dates from 1947. Compare it to 1947 cars and 1947 ladies' hats for full effect. Belluschi produced six or seven major modernist buildings here and in Salem during these years. Sort of on the side, he became a pioneering advocate for Northwest Regional style for houses and churches, those monopitch roofs and cannery-looking wood-beam stuff that would fully flower into cliche thirty years later.

In 1951, Belluschi left Portland for M.I.T. as Dean of the architecture school and built a national reputation, did a lot of high-profile corporate work through the mid 1980s, served on a lot of juries, did a lot of design consulting, won the AIA Gold Medal. Happily he was a sharp thorn in the side of Philip Johnson for decades. This disagreement boiled over in the debate over Michael Graves' benighted Portland Building in an entertaining way, but that's another story.

The design solution for the Equitable Building (now the Commonwealth) sprang from a discussion Belluschi had with the local Bonneville aluminum processor in the middle of World War II, wondering out loud what the hell they were going to do with all this surplus aluminum when the war was won. The client was willing, the supplier saw a new market and lowered the price, and Belluschi took his opportunity to set off this blast from the Italian future in 1947 Portland.

The result, here, is an architectural first, with an asterick, asterick, asterick. Is it the first modernist tower? No, that's the PSFS Building in Philadelphia, from 1932. First building with a curtain wall? That depends on what that means, exactly, and even if you're specifically talking about a glass curtain wall on the American west coast, there's the very odd and premature 1918 Hallidie Building in San Francisco, miraculously still standing. The first fully air-conditioned high-rise? No. The Milam Building, San Antonio, 1928.

What the Equitable Building is, is the first glass box. It represents an aesthetic achievement, not a technical achievement -- or, better said, the technical innovations were secondary. It's the first perfect high-rise box where the walls are flattened to the point of seeming de-materialized, and the finished structure looks like a diagram of itself. (According to Belluschi, it was also the first major high rise whose windows didn't open.)

Mies with his "purity of form" had been hunting the same kind of perfection, but Mies had lingered too long in wartime Germany, and was thorough to the point of being dull-witted. Belluschi simply beat him to the punch. The Lever House came in 1951, the Seagram Building came in 1958, to great cascades of publicity, because the glass box had happened in New York, see, so it had finally really happened. Then suddenly there were glass boxes of declining quality all over the place, undercutting the visual shock, and making the Equitable seem merely ordinary.

The Equitable is Belluschi's finest building. A survey of his other Portland work from the same era turns up this: the Psychology Building on the Reed College campus, also 1947.

The Psychology Building is comically Miesian, not an homage as much as a pitch-perfect razzing impersonation, and derives part of its considerable charm from the way it seems to hang back on its site. Belluschi knew the site well -- his stripped-down Gothic library from 1930 stands about 40 paces from here. You'd never guess the same office produced both.