"I'm a little lost ... what is the hearth method?"

delayed response...
prior to sophisticated fixturing, a real oxymoron, frames
were pinned, or tacked, or pre-set, and then taken to the
hearth, a collection of bricks which looked like a mini-
amphitheatre, and the joint-to-be-brazed was laid, (heh,
heh-heh, he said 'laid'), up against one side, and then brazed
while the non-heated side would receive the 'reflected' heat
from the bricks. it served to keep the heat 'in the joint'.
this way when you're up to the 'let's go' temperature, you
could maintain it as you finessed the rod through, and the
around, the joint. i mean the lug.
what's a lug?
bueller? bueller?