The cause of action set out in the declaration is not for digging a ditch whereby the water was diverted from the plaintiffs’ swamp, but for diverting the water of a brook or ancient watercourse, which the plaintiffs “ used to have and now ought to have running through their said swamp.” The gist of the cause of action is for a diversion of the water of a stream or watercourse. This was an essential and material averment, which the plaintiffs were bound to prove in order to maintain their action, and it was a variance to show that the acts of the defendants had drained water from the swamp without any proof to sustain the allegation of a diversion of water from a brook. It is true that the declaration alleges that the swamp was injured by the diversion of the water; but it is the “ said mater,” that is, the water of the brook which it is averred had *591been thus diverted by the act of the defendants. The instructions were therefore well adapted to present to the minds of the jury the precise question on which they were to pass, and are not open to exception.

Exceptions overruled.