Whenever there shall be any surplus money in either the fire department fund, general fund, or police department fund, now or hereafter created by virtue of the laws of this state, in any unincorporated town, the town board or board of county commissioners may, and they are authorized and empowered to, transfer such surplus, or any portion thereof, from any one to either of the funds, in the manner and proportion best calculated, in the judgment of the town board or board of county commissioners, to subserve and protect the credit of the other.