That after a consensus of opinion is ascertained, by and through the representatives of the laboring people and the trustees, as to what amount of money it is advisable that each class of laborers in, around and about the coal mines shall contribute to maintain this miners' home or homes, then the trustees of such home or homes shall have blanks prepared for the said miners and others working around the coal mines to sign, whereby said employé shall assent to the amount to be collected from his earnings by the said employer and forwarded to the state treasurer of Pennsylvania.