In the absence of evidence that the disputed line was part of the boundary of an original lot, or an extension of or parallel to such a line, the course of the original lot lines was irrelevant to any issue which could have been before the jury. A verdict is not set aside for the admission of immaterial evidence not shown to be prejudicial or used for a purpose for which it is incompetent. Rogers v. Kenrick, 63 N.H. 335. But though having no logical tendency to prove any matter in dispute, the error does not appear to have been harmless. From the manner in which the evidence was introduced and the use attempted to be made of it in argument, to which exception was also taken, the jury may well have thought they were authorized to consider the substantial identity of the course of the line upon which the brush fence was built with the course of lines bounding original lots, as having some tendency to prove that the line so marked was a divisional line. Such use of the evidence would plainly tend to prejudice the objecting party and to render the trial unfair.

Exception sustained: verdict set aside: new trial granted.

All concurred.