The appraisers, immediately after their appointment, shall be sworn and view the damage done. They may take the evidence of any witnesses of the facts and circumstances necessary to enable them to ascertain the extent of such damage, and the insufficiency of any line fence on the premises where the damage was done, if any dispute shall arise touching the same, and may administer oaths to such witnesses. They shall certify, under their hands, the amount of such damages, and the costs of keeping such beasts to that time, with their fees, not exceeding $1 per day each; and their determination as to such damages, and the sufficiency of such fence, if in dispute, shall be conclusive.