In a message dated 5/1/2005 1:52:16 PM Eastern Daylight Time, [log in to unmask] writes:

I would think there's a good possibility that the frou-frou sections you're amazed by could have been made up (and soldered together) from smaller pieces which might've been easier to fabricate in whatever sort of presses they had.

it's not the size of the section that interests me, but rather the pressing of the sheet of galvanized into what I think is called a complex conic section, where the flute spiral around the axis (as opposed to just up and down).

Cast iron, being poured, offers itself nicely to such a mold. But galvanized iron, being pressed from flat sheets, seems difficult to mold in this way.

c