When a private road has been laid out, or shall hereafter be laid out, in accordance with, and under authority of and proceedings under, act of fourth April,¹ one thousand nine hundred and one, and act of seventeenth May,² one thousand nine hundred and one, to reach bituminous coal, iron ore, fire clay, kaolin clays, stones, marbles, and sands, that, in addition to use of teams on said road, the parties owning or occupying, by lease or otherwise, lands containing said materials, may construct and operate, within and upon said private road, a tramway or tramways, or other devices, to move and carry, over, on and upon, said roads, the said materials mined and taken out of said lands: Provided, however, That nothing herein contained shall authorize or permit the operation of such tramway by locomotive: And provided further, That none of the provisions of this act shall apply to any private roadway over or across or adjoining farming lands.