Troupes are reviving the art in Philadelphia.

It is late at night in Fishtown, and outside a former elevator factory, fire-eater Brother Alejandro DuBois hunches before a scant crowd and douses his torch. As a patrol car slows, he strikes a match, causing the officer to stop and peer from the window.

Serving as ringmaster for the circus sideshow brewing inside, he explains, "We're going to spit some fire real quick." Then he adds, "Want to see?"

The officer cruises off.

The fire-eater smirks, then, dressed simply in black and white, his dreadlocks tied back, he pours a clear liquid into his mouth. Striking a dramatic pose, like a wolf baying at the moon, he brings the torch to his lips, and blows a big ball of orange fire into the night sky.

He blows again, again to cheers. In a sort of finale, in a hissing sound, he puts both flames out on his tongue. Then he announces, smiling wildly: "Ladies and gentlemen, it's showtime!"

This mini-revival, billed as Phantasmagoria Circus Side Show, takes place first Fridays inside this cavernous warehouse on Frankford Avenue, near Girard.

The Philadelphia troupe of circus arts, aerial performances, and burlesque is one of a handful in the city, and part of a growing underground circus world.

The group formed about five years ago in the magic of Coney Island. It was there that Alejandro DuBois, now 27, met Joe Lunchbox, a daredevil who lies on a bed of barbed wire and swings a bowling ball from his ear gauges, and Mariana Mystique, a young trapezist nicknamed the "aerial assassin."

Alejandro DuBois, a native of Brooklyn, N.Y., whose real name is Alexander Vargas, would go to the boardwalk to watch his cousin Serpentina charm snakes. "She recently forked her tongue," he said of her reptilian splice. Drawn to the creativity and freedom, and the shock and love from the crowd, he started doing fire performances.

The trio joined up in Philadelphia, where they met fire-eater/hula performer/stilt walker/burlesque dancer MacKenzie Moltov. This spring, their sideshow secured a monthly venue at the shuttered elevator factory, now a warehouse of new and dried tomes called Bookspace, which in recent years has evolved into an arts and cultural center.

"2011 is the year for circus performances," said MacKenzie Moltov, sitting in the warehouse one afternoon with a few core members, resembling a glamorous rag doll with her fiery ringlets.

"Circus has come back with a bang."