The testimony of the witness as to the conclusions drawn by him from what he saw was not admissible as the conclusions made by an ordinary witness from observation of things which cannot be reproduced and therefore although involving opinion admitted ex necessitate, as to which see Commonwealth v. Sturtivant, 117 Mass. 122, 133; Beverley v. Boston Elevated Railway, 194 Mass. 450; Partelow v. Newton & Boston Street Railway, 196 Mass. 24; Jenkins v. Weston, 200 Mass. 488.
Doubtless there are cases where the effect of some kinds of fire upon some kinds of material substance is not a matter of ordinary experience or knowledge such as men in general understand and comprehend. But the kind of fire pr fires which char ordinary mop-boards, sheathing and partitions and burn holes through an ordinary wooden floor without any charring or burning between
The entry must be
Exceptions sustained.