When Johnny Tremain had burned his hand & became crippled from the burning incident
How & what does Dove do to change roles in that event
Jealous of Johnny, Dove is the one who causes his accident by handing him a cracked crucible, well aware that the crack will not be able to stand the heat. His assumption was correct, and the crucible crumbled, and hot, molten silver ran down his hand. Thus, he rid himself of his competition.
"it (will) just about serve Johnny Tremain right - after the insufferable way he (has) been bossing everybody - if the crucible (gives) way and the hot silver...spill(s) all over the top of the furnace", making Johnny "look like a fool". (Dove)
Johnny Tremain
