Very large, shallow vessels were used to manufacture salt--that is, they were filled from some salt-spring, and then the water was evaporated, leaving the salt.
(shallow vessels; to manufacture; salt) (the water; was evaporated; T:then) (they; were filled; from some salt-spring) Context(they were filled,List([68, 84))):(shallow vessels; were used; to manufacture salt)
they were filled,List([68, 84))
shallow vessels the water they shallow vessels
to manufacture was evaporated were filled were used
salt
T:then
from some salt-spring
to manufacture salt