Well, what exactly are we learning in New York these days? Construction companies used to install cranes in the middle of their sites, safely erecting buildings around them. Today greed compels the real estate moguls to strap their cranes to the sides of their towers, speeding up the building process -- unless the cranes should topple into our concrete killing fields.

Ugly glass apartment buildings sprout up citywide, because only this kind of design is allowed to bypass the rules of the City Planning Commission. Last week, Mayor Bloomberg advised sweat-drenched, non-crush-proof apartment dwellers to walk upstairs to their teeny, overpriced homes, to benefit their hearts, already beating too fast from fear of being crushed or made homeless by renegade cranes.

Happily, an old and sage teacher of elfin construct, Chris Burden, sponsored by real estate giant Tishman Speyer, has just arrived from the coast to teach us valuable lessons about beauty and scale. Burden’s 65-foot-high skyscraper of erector-set tinker toys now rises at the Fifth Avenue entrance of Rockefeller Center. Burden himself braved the 98 degree heat on the concrete at the press preview Tuesday morning, instructing a handful of scribes, surrounded by employees of the Public Art Fund, handing out water in the merciless oven of Rockefella Land. Atlas, down the block, would have shrugged, but for the box Tishman Speyer has interred him in for renovation and cleaning.

Burden’s erection is a surprisingly modest jewel, a human-scaled lattice surrounded by capitalist domination. Its delicate trelliswork could easily adorn the swift wrist of one of those harridans from Sex and the City, and its structure is a tender micromimicry of the sandstone 30 Rock Tower in the sightline behind it.

The message of Burden’s sparkling conceit is that small is beautiful, harmony uplifts, symmetry is the soul of art while glass is ugly and redundant. Better to shimmer in metal. Also, shut out the noise and learn at your own pace. Downtown, there’s a kid artist who agrees.