但诗人写诗是遵循语言规律的--

但诗人写诗是遵循语言规律的， 不然他们的诗会无法被理解。 会有特例， 但特例也被包容在诗作容许的范围内， 因为写诗必然是给人看的。

In the line "with a slam and flick to beat real iron out, to work the bellows" :
                              A                               B                          C
A can be use to describe B or both A and B.  A cannot describe C only.  The sentence structure determins this.