§ 121. Commissioners of appraisal to be appointed. Upon such presentation, such court shall, after hearing any person owning or claiming an interest in the lands to be acquired who may appear, appoint three disinterested persons as commissioners of appraisal. And in case a commissioner of appraisal shall at any time decline to serve, or shall die, or for any cause become disqualified or disabled from serving as such, the said court, at a similar special term, may, upon similar notice, application and hearing, and upon such notice to the land owners as the court may prescribe, appoint another person similarly qualified, to fill the vacancy caused thereby.