Brooklyn, NY. Building is attached on one side. There's a stack w/ 4
openings in between the buildings. One opening is the other building's
boiler flue, the next opening is sealed up, the next opening is a flue
that appears to go all the way down, the fourth opening is sealed.

I want to figure out who's flue the open one is. I don't think it is in
use, and I don't think the owner of the other building will know. Is
there a rule of thumb for how they arranged old flues? doubtful.

Assuming its all sealed up, any way to figure it out?

Eventually I might like to run a hood vent up there, is the main reason
I'm interested.

any info appreciated,

Ben