umpire vs referee

The submission under the rule of court did not contemplate the third referee to be a mere umpire in the case, upon a difference of opinion of the other two; but an original referee, to be chosen by the other two, and when chosen, to constitute a part of the board authorized to hear and decide the cause... and if the case were one in which an umpire was to be chosen, there is no impropriety, and on the contrary it has been thought that there is great propriety, in selecting the umpire before the other arbitrators have disagreed.