If any Tenant or Occupier at a Rent join in the Application for an Improvement, or by Writing under his Hand signify to the Commissioners, or to an Assistant Commissioner or Engineer, his Consent to become charged with the Charge, or an apportioned Part thereof as herein-after mentioned, such Tenant or Occupier shall during his Tenancy or Occupation be liable to pay the Charge, or an apportioned Part thereof as herein-after mentioned; and in case the Charge be made in respect of the Improvement as well of other Land as of the Land included in such Tenancy or Occupation, the Commissioners may, upon such Consent of the Tenant or Occupier, declare in the Absolute Order what Portion of the whole Charge payable in respect of the Improvement shall be payable by such Tenant or Occupier during his Tenancy of Occupancy in respect of the probable Improvement of the Land included in his Tenancy or Occupation; but, except as aforesaid, every Tenant or Occupier who pays such Charge shall be entitled to deduct the Amount thereof from the Rent payable by him to the Landowner, and shall be allowed the same in Account with him.